Hey guys, its been a cold winter, and it looks like spring has come a little early. It feels so good too! It also feels great to let everyone know that our end of year inventory is over and we are again fully stocked with all the essentials you need for your grow room. We are also gearing up for what is anticipated as the biggest grow season ever. Viva 2010, with outdoor and indoor projects being taken on in extremely aggressive levels, its super exciting for us to be able to provide for all the Sonoma County growers and beyond who are getting involved. We have -

• Traditional soils, organic blends, soilless blends, rockwool, and coco pots ready to go.
• Grow lights, electronic ballasts, magnetic ballasts, reflectors, high output fluorescent systems, LED Grow lights, replacement bulbs.
• Hydro trays, containers, smart pots, complete hydro setups.
• Complete organic and hydroponic nutrient lines – General Hydroponics, General Organics, House and Garden, Cutting Edge, Technaflora and tons of grow and bloom enhancers and accelerators.
• Carbon filters of every size and shape
• Wall, pedestal and exhaust fans and blowers of every shape and size
• Ducting, clamps, foil tape, flanges, reducers, extenders, splitters, splicers
• Co2 generators, controllers and parts
• Organic and chemical pest control products
• Master light controllers, Environmental controllers, High temp. shut off devices
• Water purification systems, accessories and replacement filters
• Ready to grow, self contained Darkrooms
• Valves, elbows, tees, custom hydro fittings, replacement sprayers and misters
• Full service repair dept. complete with loaner ballasts
• Full time accredited botanist

We love to serve and provide the best advice and products available in the indoor/hydroponic/organic gardening industry, give our friendly grow experts a call today and let us know how we can help you. 1-866-PGS-GROW

Beat the winter blues this year by creating your very own salad factory that can run 365 days a year! Keith Roberto, author of “How To Hydroponics,” takes us through the process step-by-step.

There are many ways to grow lettuce hydroponically. Here’s a system that’s simple, inexpensive ($20-$30 complete) and “complex” enough to satisfy any first timer’s appetite for a fun project that actually works pretty well. It’s called the “Raft System.” In concept, the raft system does exactly as it says. Plants are grown in Styrofoam “rafts” that float in a shallow pool of nutrient solution. To keep the nutrient from stagnating, a small air pump is used to deliver oxygen to the solution and the eagerly awaiting roots.

Parts List

(1) 14 Gallon Roughtote reservoir
(1) Single outlet air pump (Elite 801)
(1) 2’ x 2’ x 1.5” rigid foam sheet
(9) 2” net cups
(1) 6’ x 1/4” air tubing
(1) Air stone
(1) Small bag of LECA
(9) Seed starting/rooting plugs
(1) 1/4” compression grommet
+ Hydroponic nutrients

Tools You’ll Need

Electric or battery powered drill
3/8” or 1/2” chuck 1 7/8” hole saws for cutting plant sites
3/8”drill bit for drilling grommet hole
Jigsaw or coping saw for cutting foam
Razor knife for cutting tubing
A pen or marker

Step 8: Fill ‘er up! Add water, nutrients and plug in your pump: your raft garden will start gurgling and your plants will grow in no time – don’t forget to give them plenty of light and top off the nutrient solution every time it drops 2-4” or so. It’s also a good idea to completely flush and clean your raft system every other harvest using a 10% bleach solution and scrub brush.

The Perfect Environment For Lettuce

Temperature: Lettuce prefers cooler temperatures. It bolts rapidly if things get too hot, especially if temps exceed 80 to 85°F (27 to 29°C). Ideal temps for most commonly grown varieties: 64 to 70°F (18 – 21°C) during the day and 55 to 61°F (13 to 16°C) at night. Higher temperatures can also cause burning on the leaf tips.

Relative Humidity (RH): 60 to 80 percent.

Nutrient Solution pH: 5.5 and 5.8 and EC from 0.6 to 1.0

Lighting: Compact fluorescents are ideal for the production of salad greens indoors. Lights should be switched on for 14-18 hours per day. Increasing nitrogen levels if growing under longer day lengths will speed up growth significantly.

Eager for more DIY hydro-projects? Check out Keith’s website, and stay tuned for more weekend projects from Urban Garden Magazine!

Hydroponic plants can enrich the lives of animals just as they do humans, and what better place to exhibit this than at a zoo. Paignton Zoo Environmental Park in Devon, UK, recently hosted the official opening of the Verticrop vertical hydroponic farming system, developed by Valcent EU. The idea of growing fresh food for the animals on-site originated from discussions between Kevin Frediani, curator of plants and gardens at Paignton Zoo, and Valcent Products (EU) Ltd., based in Launceston, who was developing a vertical hydroponic system for high intensity cropping. Space within the zoo was tight and at a premium, so options for on-site fresh food production were severely limited until the vertical cropping was introduced by Valcent. Within a small area in the middle of the zoo, which was formally a goat paddock, a 395 square foot greenhouse was erected in May 2009 and the system began installation in August. By the time of the opening on September 30, an impressive growth rate had ensured some sizeable lettuce was ready for viewing and for taste testing by the zoo occupants.

With an annual bill for animal feed currently in excess of $300,000 a year, it is the hope of management the high intensity Verticrop system will not only produce ultra fresh produce on-site, but also reduce both food miles and food costs for the zoo. Lettuce has been the initial trial crop for the Verticrop system, with many animals enjoying the fresh crunch of crispy green leaves. The zoo currently goes through 800 lettuce heads per week, $12,000 worth of fruit per month and also uses fresh herbs as enrichment for many species. Later on it’s planned that the hydroponic system will have more diversity of crops; currently small volumes of basil and other leafy greens are being trialed.

Nutrient solution flows through the trays, past the plant roots and is channeled to the end were it is collected and drained away for recirculation. The movement of the stacks or rigs of trays, filled with lettuce plants, around the greenhouse to the nutrient delivery bay is a feature of the system which has great audience appeal as the many spectators who pass the greenhouse in the midst of the zoo grounds are testament to. The system features not only new technology in terms of rigs, conveyors, tray loading machinery and customized growing channels, but also incorporates high technology growing greenhouse equipment such as UV nutrient treatment, filters and automated nutrient and greenhouse control. A ‘touch-screen’ monitor linked to a Priva computer gives control over the nutrient dosing, greenhouse ventilation and the conveyor system. This system allows groups of growing trays to receive different irrigation programs so that young seedlings or different species can be dosed with fewer nutrients than those rigs containing larger plants. The Priva system also controls the under floor heating system. Another interesting feature of the Verticrop system is the custom made tray handler, which allows the growing trays to be loaded and unloaded from the rigs, four at a time; this should allow for commercial Verticrop systems to become fully automated.

Based upon technology originally developed in the Valcent Group’s research centre in El-Paso, Texas, much of the current success of the system can be attributed to Valcent’s UK team led by horticultural development manager Grahame Dunling, who with many years of experience as a grower and manager was fully aware of the challenges involved in designing high intensity solution culture systems. Grahame’s knowledge and expertise saw the development of customized growing trays, which are a unique feature of the system and has made the many modifications and improvements required to get the Verticrop system fully operational. Along with customized growing trays, the system will incorporate the use of the latest technology in soilless growing media. Because the final product is destined to be fed, roots and all, to the animals, the media used to raise and support the seedlings needs to be suitable for this purpose. Rockwool has been avoided for this reason, and it is intended that hydroponic seedling media made from a cellulose fiber derived from wood is to be used, which can be fed to the animals once the crop is harvested.

“Manipulations of the nutrient solution and environment could enhance the fiber, vitamin and beneficial nutrient levels and phytonutrients in the fresh greens.”

While growth through summer in the multi-level system has been rapid, it is planned to trial LED supplemental lighting as the season progresses into the shorter days and lower light levels of the UK winter. Valcent has been working in association with Philips to trial new LED technology, which is hoped will lead to the development of a commercially viable lighting arrangement for the Verticrop system.

Initially several varieties of butterhead and loose leaf lettuce were trialed to determine which would produce the best `fodder crop’ for the zoo animals. While hydroponic lettuce destined for supermarkets and consumers needs to meet specific qualities of long shelf life, compact heads and acceptable weight, fresh produce for the animals is a little different. The vegetables, herbs and other produce grown on-site can be harvested and fed out immediately, guaranteeing the animals have salads fresher than most zoo-goers will ever experience. While there might be less of a concern over extended shelf life and compact heads, there is interest from zoo staff and researchers in using the system to not only enrich the lives of the animals with fresh produce, but also to manipulate the nutritional quality of the vegetables being grown in the Verticrop system. With hydroponics and protected growing environments, there is much more control over plant nutrition than there is with soil grown crops. Starting with a base of good quality water, the nutrient solution can be manipulated to influence the compositional quality of the hydroponic crop and whether this is for animals or for improving human nutrition it is an idea which has increasing appeal to many.

Kevin Frediani, curator of plants and gardens at Paignton Zoo is particularly interested in the nutritional quality of fresh fodder and is hoping that the Verticrop system can be used to address problems such as `hemosiderosis’ in zoo animals. Hemosiderosis is a worldwide problem in zoos where certain animals, who are no longer dining on the food of their native habitats, end up consuming too much iron, which ends up stored in body tissues. This iron builds up in organs such as the liver where it stays permanently and causes severe tissue damage over time. While zoo animals can be fed commercial premixes low in iron, the fresh fruits and vegetables fed to many animals as part or all of their diet typically contain more iron than is needed. With fruit, vegetables and herbs being an important part of not only captive animals diets, but as part of the enrichment and activity programs, the issue of iron levels and hemosiderosis can become widespread in some species. This problem is further compounded at Paignton Zoo as vegetables grown locally in the deep red, iron rich soils of Devon are higher than normal in iron, and in general commercially-grown vegetables worldwide produced with soil fertilizer additions would be expected to have higher iron contents than the vegetation many zoo animals consumed in their native environments. With hydroponic systems and starting with RO, distilled or rainwater (free from naturally occurring iron in the water supply) it is relatively simple to lower iron in the solution to levels where plant iron deficiency and growth reductions are limited, but the resulting tissue has minimal iron levels, making it more suitable to animals prone to development hemosiderosis. Further manipulations of the nutrient solution and environment could see improvements in dry weight, fiber, vitamin and beneficial nutrient levels, phytonutrients, chlorophyll and other health related factors in the fresh greens that are difficult or impossible to achieve with commercially prepared dried animal feeds.

One of the most exciting aspects of the Verticrop system installed at Paignton Zoo is that is it is effectively `taking hydroponics to the people,’ zoo-goers can walk around the outside of the greenhouse and view the plants moving and growing in situ. This is particularly relevant to Paignton Zoo which is also a botanic garden keen to education people about all aspects of horticulture and the impact on our environment of crop production. Public viewings of large scale hydroponics are rare and while many people are aware of soilless culture, few have the option of seeing high intensity crops growing in real life. At a later date, a web cam installed on the greenhouse ceiling will provide a live feed on the zoo’s website, allowing visitors ongoing viewing of plant progress. Good publicity regarding hydroponics is always a bonus and at Paignton Zoo; healthy lettuce at all stages of development can be seen and the story of how the animal’s lives are enriched by on-site fresh produce is told. The fact that the Verticrop system is the first high intensity vertical hydroponic system of its kind installed in a zoo anywhere in the world makes it a great addition to Paignton Zoo’s attractions.

Hey guys, today I present an educational, in-depth, up-to-date, indoor horticultural growers guide that covers all principles of indoor hydroponic horticulture and gardening. This book contains 110,000 words, with over 300 diagrams, pictures, illustrations, graphs, tables, 3 dimensional CAD renderings, and is printed in full colour.

I was really impressed at the amount of great info available in this book, I strongly recommend it for all PGS blog readers.

This book goes further than most other indoor growers guides have gone before, presented in full color with 3 dimensional CAD renderings. In terms of literal content, quantity, quality and presentation, this book is a gem!

Organic Hydroponic Vegetables

The debate on “Organics” and “Hydroponics”

There is a huge popular debate about the value of “organic” fertilizers and methods, many people would like to apply “organics” to hydroponics. Currently accepted organic fertilizer
components are dependent upon organisms in the soil to convert the “organic” materials into a useable form for plants.

In hydroponics we provide the minerals required for plant growth directly, completely eliminating the need for soil and soilorganisms. The result is much higher growth rates, yields and even crop quality than organic methods can achieve. This is not what some people want to hear, but it is the simple scientific truth – and practically all scientists and educators in the fields of agriculture and chemistry know it and will be the first to agree. In fact, the kinds of materials which are permitted for use under “organic” regulations are not of sufficient purity to be used for hydroponic culture.

With this in mind it’s important to recognize the reasons that “organically” grown produce is gaining such popularity. Consumers want to buy produce which is not tainted with hazardous chemicals or poisons. There is an increasing public demand for methods which are gentle on our delicate planet and which don’t harm the soil, water or ecosystems. Hydroponic farming methods fit properly into this system of values if used appropriately. Hydroponics protects soil because it doesn’t use soil.

Less water is required for hydroponic culture and consequently more food can be cultivated with less water. The fertilizers we use for hydroponics are ultra-pure and leave no residue in the cultivated fruits and vegetables. Since hydroponic technologies are more efficient than soil methods, more people can be fed with less area and ecological impact.

THE ORGANIC HYDROPONIC DEBATE OPENING PANDORA’S BOX

As seen in the Growing Edge Magazine During the 1980’s, Americans increasingly became more healthconscious. Cholesterol was ruled out and exercise became a part of our daily routines. Today this still holds true, but even more so. What we put into our bodies is carefully scrutinized, even our fruits and vegetables, which has made “organic” a buzzword of the ‘90s. People are buying organic skin care products, “organic shampoos” and even “organic clothing”. Everybody seems to want “organic” and hydroponic growers are quite aware of this.

Why, then, are there hardly any “Certified Organic hydroponic growers” in the United States? Many go through a great deal of trouble to grow their crops “organically,” but even though they follow most guidelines, they still cannot get the recognition or certification necessary to sell their produce to most restaurants or natural food stores as “organic”. What is it that is separating organic from hydroponic methods? Why can’t these two technologies work together under today’s American states’ certification guidelines?

WHAT’S ORGANIC, WHAT’S NOT?

We would think that this is an easy question to answer, but it isn’t. In the United States there are numerous different definitions of “organic”, many of which differ significantly. Each state has its own regulations for labeling produce as “organic”. Additionally, there are 36 non-governmental organizations which can certify” produce as organic. For example, California growers who wish to sell their produce as “organic” must register with the California Department of Food and Agriculture and pass their inspection. However, California grower’s can also obtain certification through the California Certified Organic Farmers (CCOF), which actually has higher standards for organic than the state has.

The CCOF certification is optional, but produce with California state registration and CCOF certification may be offered for sale within the state as “certified organic” If the grower chooses not to seek CCOF certification, the produce can be offered for sale in California as “organic,” but not “certified organic”. Any produce grown outside of the United States can be sold as “certified organic” in the country if one of the 36 non-governmental organizations certifies it. In fact, produce from any state can be granted certification from one of the non-governmental organizations, even if it does not meet the organic standards for the state in which it is being sold. Pretty confusing!

What this all means is that the “organic” label is a matter of bureaucratic definitions, which can vary from state to state, and country to country. In order to bring some kind of standard into play, the U.S. Department of Agriculture (USDA) – along with state government regulators, non-governmental certifiers, consumers, industry interest groups, food processors and various special interest groups – is writing a federally mandated set of “organic” standards. No state will be able to apply more stringent standards than those of the federal. Sometime this spring, the federal standards will be released for a 90 day comment and review period, and by the end of 1996 or early 1997, these standards will become law, or “Frankenlaw”; we’ll have to wait and see.

The basic objectives of “organic” practice include the following:

Avoidance of pesticides, by use of natural pest controls (also applied by many hydroponics growers).

Caring for soil by recording nutrients and composting, and

Moderation of nutrient application with reliance on the bufferaction of humus derived from compost.

Soilless hydroponic cultivation moderates nutrient supply by the more exact measurements of soluble nutrient formulations, mixed to meet the optimum requirements of each plant species and growth phase. Many consumers select “organic” produce, believing that this is the only way to be assured of pesticide-free non—hazardous food. While “organic” farming methods do produce crops generally superior to and safer than those grown by agri-business practices, modern hydroponic techniques can put forth equally safe food that in many cases offers advances in nutrition and taste over their soil-grown “organic” counterparts. But to the consumer, it’s the label that counts, so an increasing number of growers throughout the United States are struggling to get organic certification in any way, shape or form.

Meanwhile, this whole situation poses an enormous dilemma to hydroponic growers who also want organic recognition for their produce. The primary problem for organic hydroponic growers is in the formulation of the soilless nutrient solution. A secondary issue, which concerns the federal regulators, is in the way used hydroponic nutrient and media such as rockwool are disposed of. Since “organic” is to a large extent a farming philosophy in support of a healthy environment, the federal concern is entirely reasonable.

Although the latter factor has no bearing on the quality and safety of the produce itself, the impact upon the planet is a real driving force behind the issue of “organic” farming. If hydroponic growers can find a way to completely recycle exhausted water, nutrients and media, then the argument in favor of “organic-hydroponic certification” becomes much stronger, but there’s still the issue of formulating a satisfactory organic hydroponic nutrient mix.

Organic nutrient regulations prohibit the use of many mineral salts and highly refined substances, including food and pharmaceutical grade ingredients that are extremely important for successful hydroponic nutrient formulation. Only unrefined minerals can be used on “organic” crops and these often don’t dissolve well or contain quantities of impurities, some of which are even relatively toxic but are “natural” and therefore “okay”, according to organic standards. For example, mined phosphate may contain excessive amounts of fluoride, good for teeth in very small quantities, but harmful to humans in excess.

Mined phosphate also can contain small amounts of radioactive elements such as radium, which releases radon, also not good for human health. Chlorides, too, are permitted for organic cultivation but though they are naturally mined, they can be bad for both plants and soil, especially if used in excess. Some soils used by organic farmers contain such toxic elements as selenium, which can accumulate in the plant tissues and produce. Amazing, isn’t it?

When refined, any impurities or toxicities such as those listed above are removed, but refined minerals make for non-organic produce. Blood meal, bone meal, fish meal and manures pose almost no potential safety hazards, but they don’t dissolve very well; they must be broken down through microbial action in the soil and therefore don’t work well in hydroponic applications. There is also a problem that sometimes arises when using manures. The Western Fertilizer Handbook, an important guide for American farmers, points out that many gastro-intestinal illnesses can he traced back to manures used on organically gown crops.

In the summer of 1995, a serious outbreak of salmonella poisoning resulted from an organic cantaloupe crop growing in soil fertilized with fresh chicken manure. The rinds of the melons had become contaminated and the bacteria caused serious intestinal illness for many consumers.

Another point that can be made is that strict vegetarians or animal rights activists may be offended by the use of blood, bone, horn, hoof and feather meals to grow their food, but these are primary nutrient sources for organic farmers. As you can see, this issue Is very complex and there are many points of view. Essentially though, “organic” farming is part philosophy and part methodology, but unfortunately defined bureaucratically.

Look out for Part 2 Tomorrow!

]]> http://pgsgrow.com/blog/2009/11/24/organics-and-hydroponics-can-they-work-together/feed/ 2 http://pgsgrow.com/blog/2009/11/19/custom-build-your-dream-indoor-garden-with-pgs/ http://pgsgrow.com/blog/2009/11/19/custom-build-your-dream-indoor-garden-with-pgs/#comments Thu, 19 Nov 2009 19:53:03 +0000 Pete http://pgsgrow.com/blog/?p=1271 Ok, so you have grown a few crops and now your ready to maybe “kick it up” a little. Sounds good, we all get to that point, and building an indoor hydroponic, or container garden from scratch can not only be fun, but incredibly rewarding as well. Instead of mapping out different systems for you guys, and explaining features, I going to work from the premise that you guys are familiar with the equipment we will be featuring today. I want to show you how PGS has everything necessary to help you design your dream grow room.

Galaxy Electronic HID Ballast

Lets start with the foundation of any indoor garden, lighting…First thing is first, electronic ballast, or magnetic ballast. We have both types stocked in 600 and 1000 watt varieties.

Harvest Pro Magnetic HID Ballast

Next thing to consider….Light Reflector. We carry a HUGE line of options, priced competitively. We can help you determine the optimal reflector for your situation based on 20+ years of experience.

HID Reflectors Stocked and Ready

Moving on to…. grow method. If your a die hard organic soil or soil-less fanatic, or a hydroponic scientist, we have a complete stock of containers, hydroponic mediums, and complete systems to meet anyone’s needs.

Next Step… Ventilation.
Anyone serious about growing indoors knows that ventilation is one of the most important things to take seriously. PGS has got you covered. Dampers, Filters, Extenders, Fans, Clamps, Reducers, Controllers and more….

Lets continue on to CO2 Enrichment… Tired of small yields and airy product? Increase your yields and overall structure with CO2 enrichment. We carry a large line generators, tanks, regulators, and controllers.

Little things that make the difference between bumper crops and bogus results.

Keep your plants happy and healthy through the entire bloom cycle!

Now lets address Environmental Control….
Now that you have a great room in the making, don’t let the environment go to shit with neglect! Dial in the perfect temperatures, humidity levels and your electricity to run flawlessly at all times. PGS has any kind of controller for your environment you can imagine.

Get Notified While Your Gone If You Have a Fire or a Breakin

Onto… Propagation What good is all of this without clones and cuttings to get your future crops ensured? PGS carries popular aero clone machines, as well as tradition Oasis, and Rockwool cubes, clone solutions, gels, and powders, modern T5 fluorescent systems and more…..

The key to success over a long period of time, is an intelligent, planned out nursery program, that includes all the things you would address in your bloom or vegetative environment. Temperature, co2 levels, relative humidity etc… Your future crops are only as good as the plants your nursery produces! Take the extra time to really create a perfect nursery and you will enjoy years of massive crops and prosperity!

T5 Fluorescent Grow Lights - Perfect For Vegetative Growth and Propagation

Let’s not forget the staple of ALL gardens.. Nutrients

Ah… what to say about nutrients? Take the time to learn what works best for your particular situation. We can help, we have just about every major plant nutrient product that is available today, AND we know how to use them.

Perhaps you want a ready to go Growroom? There are some really great ready to go grow rooms that are easy to assemble, and easy to break down. They make alot of sense for even the most experience growers in some situations. They come in every size for any project… Including massive Mammoth size ones for epic projects.

Don’t let garden pest ruin all your have built!… Pest Management.

After all your doing to build this dream room, don’t let bugs ruin this scenario! PGS has a full arsenal of organic and non-organic forms of pest management.

PGS Pest Managment Station

Did we almost forget Water Quality? Hell NO!

Without healthy, clean water as a basis, you will NEVER have a bumper crop. PGS has simple pacific sands filters, to full on huge RO systems.

Ok, I could go on and on about all the rest of the odds and ends, but the point is WE HAVE IT, from white plastic, Mylar, timers and fittings. Above all we offer a smile, and countless years of combined experience. Call us for prices and tell them Pete from the blog said to give you a deal!!! 1-866-PGS-GROW

]]> http://pgsgrow.com/blog/2009/11/19/custom-build-your-dream-indoor-garden-with-pgs/feed/ 0 http://pgsgrow.com/blog/2009/11/18/keep-humidty-out-of-your-room-with-a-55-gallon-drum/ http://pgsgrow.com/blog/2009/11/18/keep-humidty-out-of-your-room-with-a-55-gallon-drum/#comments Wed, 18 Nov 2009 18:20:15 +0000 Pete http://pgsgrow.com/blog/?p=1267 All the little things you do to improve your indoor garden add up over time and directly equate to a better harvest and higher quality product. Humidity can build up in your room from many different sources, one of the major ones is your reservoir. A simple lid on your res can drastically reduce the escaping humidity but a better solution is to remove the water source from your room completely. This gives you extra space in your garden, and removes the water completely from the equation. This 55 gallon drum is made of food grade plastic, and fits easily anywhere outside of your indoor garden, you can then run a hose from it to your room, and you instantly have removed extra humidity while reclaiming valuable space in your garden. I recently implemented this concept and have room now for bigger plants, and have lowered my humidity in one fail swoop.

The more you know, the easier it is to grow!

Carbon Dioxide

During photosynthesis, plants use carbon dioxide (CO2), light, and hydrogen (usually water) to produce carbohydrates, which is a source of food. Oxygen is given off in this process as a by-product. Light is a key variable in photosynthesis.

Conductivity

Measuring nutrient solution strength is a relatively simple process. However, the electronic devices manufactured to achieve this task are quite sophisticated and use the latest microprocessor technology. To understand how these devices work, you have to know that pure water doesn’t conduct electricity. But as salts are dissolved into the pure water, electricity begins to be conducted. An electrical current will begin to flow when live electrodes are placed into the solution. The more salts that are dissolved, the stronger the salt solution and, correspondingly, the more electrical current that will flow. This current flow is connected to special electronic circuitry that allows the grower to determine the resultant strength of the nutrient solution.

The scale used to measure nutrient strength is electrical conductivity (EC) or conductivity factor (CF). The CF scale is most commonly used in hydroponics. It spans from 0 to more than 100 CF units. The part of the scale generally used by home hydroponic gardeners spans 0-100 CF units. The part of the scale generally used by commercial or large-scale hydroponic growers is from 2 to 4 CF. (strength for growing watercress and some fancy lettuce) to as high as approximately 35 CF for fruits, berries, and ornamental trees. Higher CF values are used by experienced commercial growers to obtain special plant responses and for many of the modern hybrid crops, such as tomatoes and some peppers. Most other plant types fall between these two figures and the majority is grown at 13-25 CF.
–Rob Smith

Germination

When a seed first begins to grow, it is germinating. Seeds are germinated in a growing medium, such as perlite. Several factors are involved in this process. First, the seed must be active–and alive–and not in dormancy. Most seeds have a specific temperature range that must be achieved. Moisture and oxygen must be present. And, for some seeds, specified levels of light or darkness must be met. Check the specifications of seeds to see their germination requirements.

The first two leaves that sprout from a seed are called the seed leaves, or cotyledons. These are not the true leaves of a plant. The seed develops these first leaves to serve as a starting food source for the young, developing plant.

Growing Medium

Soil is never used in hydroponic growing. Some systems have the ability to support the growing plants, allowing the bare roots to have maximum exposure to the nutrient solution. In other systems, the roots are supported by a growing medium. Some types of media also aid in moisture and nutrient retention. Different media are better suited to specific plants and systems. It is best to research all of your options and to get some recommendations for systems and media before making investing in or building an operation. Popular growing media include:

• Composted bark. It is usually organic and can be used for seed germination.
• Expanded clay. Pellets are baked in a very hot oven, which causes them to expand, creating a porous end product.
• Gravel. Any type can be used. However, gravel can add minerals to nutrient. Always make sure it is clean.
• Oasis. This artificial, foam-based material is commonly known from its use as an arrangement base in the floral industry.
• Peat moss. This medium is carbonized and compressed vegetable matter that has been partially decomposed.
• Perlite. Volcanic glass is mined from lava flows and heated in furnaces to a high temperature, causing the small amount of moisture inside to expand. This converts the hard glass into small, sponge-like kernels.
• Pumice. This is a glassy material that is formed by volcanic activity. Pumice is lightweight due to its large number of cavities produced by the expulsion of water vapor at a high temperature as lava surfaces.
• Rockwool. This is created by melting rock at a high temperature and then spinning it into fibers.
• Sand. This medium varies in composition and is usually used in conjunction with another medium.
• Vermiculite. Similar to perlite except that it has a relatively high cation exchange capacity–meaning it can hold nutrients for later use.

There are a number of other materials that can (and are) used as growing media. Hydroponic gardeners tend to be an innovative and experimental group.

Hydroponic Systems

The apparatuses used in hydroponic growing are many and varied. There are two basic divisions between systems: media-based and water culture. Also, systems can be either active or passive. Active systems use pumps and usually timers and other electronic gadgets to run and monitor the operation. Passive systems may also incorporate any number of gadgets. However, they to not use pumps and may rely on the use of a wicking agent to draw nutrient to the roots.

Media-based systems–as their name implies–use some form of growing medium. Some popular media-based systems include ebb-and-flow (also called flood-and-drain), run-to-waste, drip-feed (or top-feed), and bottom-feed.

Water culture systems do not use media. Some popular water culture systems are raft (also called floating and raceway), nutrient film technique (NFT), and aeroponics.

Light

Think of a plant as a well-run factory that takes delivery of raw materials and manufactures the most wondrous products. Just as a factory requires a reliable energy source to turn the wheels of its machinery, plants need an energy source in order to grow.

Artificial Light

Usually, natural sunlight is used for this important job. However, during the shorter and darker days of winter, many growers use artificial lights to increase the intensity of light (for photosynthesis) or to expand the daylight length. While the sun radiates the full spectrum (wavelength or color of light) suitable for plant life, different types of artificial lighting are selected for specific plant varieties and optimum plant growth characteristics. Different groups of plants respond in physically different ways to various wavelengths of radiation. Light plays an extremely important role in the production of plant material. The lack of light is the main inhibiting factor in plant growth. If you reduce the light by 10 percent, you also reduce crop performance by 10 percent.

Light transmission should be your major consideration when purchasing a growing structure for a protected crop. Glass is still the preferred material for covering greenhouses because, unlike plastic films and sheeting, its light transmission ability is indefinitely maintained.

No gardener can achieve good results without adequate light. If you intend to grow indoors, avail yourself of some of the reading material that has been published on this subject. If you are having trouble growing good plants, then light is the first factor to question.
–Rob Smith

Natural Light

A large part of the success in growing hydroponically is planning where to place the plants. Grow plants that have similar growing requirements in the same system. Placing your system 1-2 feet away from a sunny window will give the best results for most herbs and vegetables. Even your regular house lights help the plants to grow. Make sure that all of the lights are out in your growing area during the night. Plants need to rest a minimum of 4 hours every night. If your plants start to get leggy (too tall and not very full), move the system to a spot that has more sun. Once you find a good growing area, stick to it. Plants get used to their home location. It may take some time to get used to a new place.
–Charles E. Musgrove

Macronutrients

• • Nitrogen (N)–promotes development of new leaves
  • Phosphorus (P)–aids in root growth and blooming
  • Potassium (K)–important for disease resistance and aids growth in extreme temperatures
  • Sulfur (S)–contributes to healthy, dark green color in leaves
  • Calcium (Ca)–promotes new root and shoot growth
  • Magnesium (Mg)–chlorophyll, the pigment that gives plants their green color and absorbs sunlight to make food, contains a Mg ion
    –Jessica Hankinson

Plants need around 16 mineral nutrients for optimal growth. However, not all these nutrients are equally important for the plant. Three major minerals–nitrogen (N), phosphorus (P), and potassium (K)–are used by plants in large amounts. These three minerals are usually displayed as hyphenated numbers, like “15-30-15,” on commercial fertilizers. These numbers correspond to the relative percentage by weight of each of the major nutrients–known as macronutrients–N, P, and K. Macronutrients are present in large concentrations in plants. All nutrients combine in numerous ways to help produce healthy plants. Usually, sulfur (S), calcium (Ca), and magnesium (Mg) are also considered macronutrients.

These nutrients play many different roles in plants. Here are some of their dominant functions:

Micronutrients

Boron (B), copper (Cu), cobalt (Co), iron (Fe) manganese (Mn), molybdenum (Mo), and zinc (Zn) are only present in minute quantities in plants and are known as micronutrients. Plants can usually acquire adequate amounts of these elements from the soil, so most commercial fertilizers don’t contain all of the micronutrients. Hydroponic growers, however, don’t have any soil to provide nutrients for their plants. Therefore, nutrient solution that is marketed for hydroponic gardening contain all the micronutrients.
–Jessica Hankinson

Nutrient Solution

In hydroponics, nutrient solution–sometimes just referred to as “nutrient”–is used to feed plants instead of plain water. This is due to the fact that the plants aren’t grown in soil. Traditionally, plants acquire most of their nutrition from the soil. When growing hydroponically, you need to add all of the nutrients a plant needs to water. Distilled water works best for making nutrient. Hydroponic supply stores have a variety of nutrient mixes for specific crops and growth cycles. Always store solutions out of direct sunlight to prevent any algae growth. See also conductivity, macronutrients, and micronutrients.

Disposal Unlike regular water, you need to be careful where you dispose of nutrient. Even organic nutrients and fertilizers can cause serious imbalances in aquatic ecosystems. If you do not live near a stream, river, lake or other water source, it is fine to use old nutrient on outdoor plants and lawn. Another possibility is to use it on houseplants. However, if you live within 1,000 feet of a viable water source, do not use your spent nutrient in the ground.

Osmosis

The ends of a plant’s roots aren’t open-ended like a drinking straw and they definitely doesn’t suck up a drink of water or nutrients (see capillary action). Science is still seeking a complete understanding of osmosis, so to attempt a full and satisfactory description of all that’s involved in this process would be impossible. However, we can understand the basic osmotic principle as it relates to plants.

First, consider a piece of ordinary blotting paper, such as the commonly used filter for home coffee machines. The paper might appear to be solid. However, if you apply water to one side of it, you’ll soon see signs of the water appearing on the opposite side. The walls of a feeding root act in much the same way. If you pour water onto the top of the filter paper, gravity allows the water to eventually drip through to the bottom side. Add the process of osmosis and water that’s applied to the bottom side drips through to the top.

With plants, this action allows water and nutrients to pass through the root walls from the top, sides, and bottom. Osmosis is the natural energy force that moves elemental ions through what appears to be solid material. A simplistic explanation for how osmosis works, although not 100 percent accurate, is that the stronger ion attracts the weaker through a semipermeable material. So, the elements within the cells that make up plant roots attract water and nutrients through the root walls when these compounds are stronger than the water and nutrients applied to the outside of the roots.

It then follows that if you apply a strong nutrient to the plant roots–one that’s stronger than the compounds inside of the root–that the reverse action is likely to occur! This process is called reverse osmosis. Many gardeners have at some time committed the sin of killing their plants by applying too strong a fertilizer to their plants, which causes reverse osmosis. Instead of feeding the plant, they have actually been dragging the life force out of it.

Understanding how osmosis works, the successful grower can wisely use this knowledge to promote maximum uptake of nutrients into the plants without causing plant stress–or worse, plant death–from overfertilizing. All plants have a different osmotic requirement or an optimum nutrient strength.
–Rob Smith

Oxygen

As a result of the process of photosynthesis, oxygen (O) is given off by plants. Then, at night, when light isn’t available for photosynthesis, this process is reversed. At night, plants take in oxygen and consume the energy they have stored during the day.

Pests and Diseases

Even though hydroponic gardeners dodge a large number of plant problems by eschewing soil (which is a home to any number of plant enemies), pests and diseases still manage to wreak havoc from time to time. Botrytis, Cladosporium, Fusarium, and Verticillium cover most of the genera of bacteria that can threaten your plants. The insects that can prove annoying include aphids, caterpillars, cutworms, fungus gnats, leaf miners, nematodes, spider mites, thrips, and whiteflies.

A few good ways to prevent infestation and infection are to:

• Always maintain a sanitary growing environment
• Grow naturally selected disease- and pest-resistant plant varieties
• Keep your growing area properly ventilated and at the correct temperatures for your plants
• Keep a close eye on your plants so if a problem does occur, you can act quickly

With insects, sometimes you can pick off and crush any large ones. Or you can try to wash the infected plants with water or a mild soap solution (such as Safer Soap).

If a problem gets out of control, it may be necessary to apply a biological control in the form of a spray. Research which product will work best in your situation. Always follow the instructions on pesticides very closely.

Alternatively, there are a number of control products on the market today that feature a botanical compound or an ingredient that has been synthesized from a plant material.

On botanical compounds as controlling agents:

Over the last few years, researchers from all around the world have started to take a much closer look at any compounds present in the plant kingdom that might hold the answer to our pest and disease control problems. Many companies have even switched from producing synthetic pesticides to copying nature by synthesizing naturally occurring compounds in a laboratory setting. Extracts of willow, cinnamon, grapefruit, garlic, neem, bittersweet, lemon grass, derris, eucalyptus, and tomato have been helpful in controlling diseases and pests.
–Dr. Lynette Morgan

pH

The pH of a nutrient solution is a measurement of its relative concentration of positive hydrogen ions. Negative hydroxyl ions are produced by the way systems filter and mix air into the nutrient solution feeding plants. Plants feed by an exchange of ions. As ions are removed from the nutrient solution, pH rises. Therefore, the more ions that are taken up by the plants, the greater the growth. A solution with a pH value of 7.0 contains relatively equal concentrations of hydrogen ions and hydroxyl ions. When the pH is below 7.0, there are more hydrogen ions than hydroxyl ion. Such a solution “acidic.” When the pH is above 7.0, there are fewer hydrogen ions than hydroxyl ions. This means that the solution is “alkaline.”

Test the pH level of your nutrient with a kit consisting of vials and liquid reagents. These kits are available at local chemistry, hydroponic, nursery, garden supplier, or swimming pool supply stores. It is also a good idea to test the pH level of your water before adding any nutrients. If your solution is too alkaline add some acid. Although such conditions rarely occur, sometimes you may have to reduce the level of acidity by making the solution more alkaline. This can be achieved by adding potassium hydroxide (or potash) to the solution in small amounts until it is balanced once again.
–Charles E. Musgrove

Photosynthesis

Plants need to absorb many necessary nutrients from the nutrient solution or–in the case of traditional agriculture–the soil. However, plants can create some of their own food. Plants use the process of photosynthesis to create food for energy. Carbohydrates are produced from carbon dioxide (CO2) and a source of hydrogen (H)–such as water–in chlorophyll-containing plant cells when they are exposed to light. This process results in the production of oxygen (O).

Plant Problems

Every now and again, you are sure to run into a problem with your plants. This is just a simple fact of any type of gardening. The key is to act quickly, armed with quality knowledge.

Mineral Deficiency Symptoms

Nitrogen deficiency will cause yellowing of the leaves, especially in the older leaves. The growth of new roots and shoots is stunted. In tomatoes, the stems may take on a purple hue.

A phosphorous deficiency is usually associated with dark green foliage and stunted growth. As in nitrogen deficiency, the stems may appear purple. But since the leaves don’t yellow as they do in nitrogen deficiency, the whole plant can take on a purplish green color.

Iron deficiency results in yellowing between the leaf veins. In contrast to nitrogen deficiency, the yellowing first appears in the younger leaves. After a prolonged absence of iron, the leaves can turn completely white.
–Jessica Hankinson

Wilting

This condition can be caused by environmental factors or disease (usually caused by Fusarium). Nutrient and media temperature can be adjusted to remedy wilt. However, if Fusarium have taken hold, the chances that your plants will survive are slim.

If wilting is due to environmental causes:

Try to spray the plants and roots with cool, clean water to rejuvenate them. If this hasn’t helped them by the next day, try it again. If the plants respond, top-off the nutrient solution and check the pH. If the plants don’t respond to the misting, empty the tank, move it to a shadier spot, and refill with cool, fresh nutrient solution. Don’t reuse the old solution–start with fresh water and nutrients.
–Charles E. Musgrove

If wilting is due to a system blockage of nutrient:

I have seen tomato plants that have been so dehydrated due to a nutrient supply blockage that they were lying flat and for all the world looked stone-cold dead. When the nutrient flow resumed and the plants were given the less stressful environment of nighttime, they rebounded so well that I wondered if I had dreamed the previous day’s “disaster.” The moral of this story is to always give plants a chance to revive, even when the situation looks hopeless.
–Rob Smith

See also pests and diseases.

Propagation

Plants can be propagated by a number of methods. Growers can let a plant go to seed, collect the seeds, and then start the cycle over again (see germination). Another method is to take stem cuttings, which is also known as cloning (because you are creating an exact copy of the parent plant).

Although this process won’t work with all plants, it is a highly effective technique. Simply cut off a side shoot or the top of the main shoot just below a growth node. Make sure that there are at least two growth nodes above the cut. Remove any of the lower leaves near the base of the new plant. This cutting can then be rooted by placing it in water or in a propagation medium (perlite works well) that is kept moist. The use of some rooting hormone can help your chances of success.

Pruning

Remove any discolored, insect-eaten, or otherwise sick-looking leaves from plants. Picking off some outer leaves or cutting the top off a plant can help it grow fuller. Use sharp scissors to prune your plants. Sometimes you will want to prune a plant to focus its energy on the remaining shoots. Pruning is an art and should be performed with care. Damaged or dying roots may also need to be pruned from time to time.

Soil

Never use soil during any aspect of hydroponics. If you ever move a plant from a soil-based situation to hydroponics, remove all traces of soil or potting mix from the roots. Soil holds lots of microbes and other organisms and materials that love to grow in and contaminate your hydroponic system. Some of these will actually parasitize your plant and slow its growth. This is another advantage of hydroponic growing: The plant can get on with growing without having to support a myriad of other organisms as happens in conventional soil growing.
–Rob Smith

Temperature

Different plants have different germination and growing temperatures. Always make sure that you check each plant’s growing requirements–especially minimum and maximum temperature levels. Keep in mind that specific varieties of plants may have different requirements.

Water

Because the water supply is the source of life for your plants, quality is important. All plants rely on their ability to uptake water freely. Between 80 and 98 percent of this uptake is required for transpiration (loosely compared to perspiration in animals), which allows the plant to produce and somewhat control its immediate microclimate. Plants also need clean, uncontaminated water to produce their own healthy food supply.
–Rob Smith

The water you use in your hydroponic system needs to be pure. It is always a good idea to test your water source before adding nutrients so you aren’t adding an element that is already present. In small systems, it would be wise to use distilled water.

If you are starting a larger hydroponic operation, it would be a good idea to have a water analysis completed. Factors such as sodium chloride (NaCl, or salt) content and hardness will be of great use to growers. Also, groundwater can have elements normally not present in conditioned water. A key piece of advice: Get to know your water!