What is Hydroponics?

While the true definition varies from expert to expert, hydroponics is basically the growing of plants without soil. The word “Hydroponic” is derived from the Greek words – “Hydro” which means water and “Ponos” which means labor. True hydroponics is growing plants in water without any type of media e.g. NFT and Aeroponic, however, growing plants in soilless media such as coco, perlite rockwool etc are also classified as hydroponics.

pH stands for “Potential of Hydrogen” and is the symbol for the hydrogen ion (H+) in liquids. pH has a range from 0 (acidic) -14 (alkaline), with 7 being neutral. For hydroponics we are aiming for a pH between 5.5 to 6.2 (slightly acidic); this is suitable for most hydroponic crops. For soil, we want the pH a little higher but still slightly acidic; around 6.0 to 6.5. Ensuring that the pH remains within this range will help maintain good plant health. Keeping the pH in this range ensures that nutrients are readily available to the plant. Once the grower goes above or below this optimal range certain nutrients start becoming unavailable to the plant (e.g. iron deficiencies will appear at a pH of 6.5 and above).

All hydroponic growers need to test the pH of their nutrient solution for successful growing. The pH of a solution can be tested using a standard pH test kit (sample vial with drops of indicator solution), litmus test strips, or a digital pH meter. Litmus paper and standard test kits are cheap and easy to use; however, the degree of accuracy isn't very high. Digital pH meters, although more expensive than the alternatives, are easy to use and very accurate.

What kind of maintenance is involved with a hydroponic system?

As with soil-based production, producing crops in hydroponic systems always requires maintenance. The following list may seem like a lot of work; however, as you become experienced most tasks and checks will only take a few minutes each day.

Daily

Check reservoir for water levels, pH and TDS fluctuations.

Check grow room temperatures and humidity percentages.

If you use CO2, the CO2 system should be checked to ensure that it is working correctly.

Check watering system. If a pump fails it should be replaced immediately. If drippers are blocked they should be cleaned or replaced immediately.

Check plants for disease and insect infestations. It is always best to stop disease and insect outbreaks early. The longer an infestation is left the more difficult it will be to cure, yield losses will be high and crop failures are possible.

Check plants for leaf discoloration and deformities that may be caused by such problems as nutrient deficiencies or nutrient burn (over feeding), as well as leaf curl from lights being to close.

Crop hygiene is extremely important. Cut off and discard diseased leaves. If a plant is badly diseased, it is always better to throw out one or two plants to control disease outbreaks than it is to destroy a complete crop. The same applies to insect infestations, especially spider mites.

General maintenance - failed light bulbs, light movers, fans, loose ducting, leaks etc. should be replaced or repaired.

Weekly

The growing medium should be flushed once a week to stop nutrient lock up.

Complete reservoir change should done weekly to prevent nutrient imbalances and bacteria build-up.

Foliar spraying for disease and insect pests should be done weekly to prevent outbreaks.

End of each crop

The hydroponics system should be completely sanitized at the end of each crop. This will minimize disease carry over to the next crop.

The grow room should be sanitized with insecticides and fungicides. Walls, floors, ceilings and equipment should be wiped down to remove insects/eggs and fungi spores. The cleaner the grower is in his growing room the fewer problems he will have in the following crop.

How do I determine which system is right for me?

There are many different hydroponic systems available and it is important that you choose a system that is not only going to meet your needs but also be compatible with your growing area. In general, we recommend that novices choose an Ebb and Flow or a Top Feed/Drip System. These systems are great for beginners because they are not too complicated and they will still produce very good results. A few examples of these are the TurboGarden Ebb and Flow, or a Waterfarm Kit. Aeroponic and Nutrient Film Technique (NFT) Systems are usually only recommended for intermediate and advanced growers. These systems require much more experience and general “know how” to successfully operate. Also, because aeroponic and NFT systems use little or no growing medium, you could be in big trouble if a pump fails or the power goes out for a prolonged period of time. Growing in these types of systems can be likened to driving a racecar – you’ll get to the finish line faster than normal but if you have an accident the consequences can be devastating.

The next factor that you will have to consider is the type of plant that you are growing. Certain systems will be better suited for some plants more than others. Smaller varieties of tomatoes, basil, and certain types of lettuce are very well suited to Ebb and Flow or Drip Systems. Larger plants would work very well in Waterfarm kits or BGH Bucket Systems. Lettuce and strawberries grow exceptionally well in NFT systems. Lastly, aeroponic systems can be used with most small vegetable and flower varieties.

Finally, you will want to consider what type of system is going to work best with your growing area. You may be working with as large an area as an entire greenhouse or as small an area as a closet. It is important to consider which systems will best fit into your area. Just remember not to cram too many plants into a given area. A few healthy plants will yield more than several plants that are overcrowded. Overcrowded plants will shade each other causing them to stretch, and the lack of airflow between the leaves will hinder CO2 movement across the leaves. They will also be at a higher risk of being infected by molds and mildews. You might be able to 16 heads of lettuce or basil plants in a 2’ x 4’ area, but don’t try this with something larger like tomatoes or cucumbers.

There are many advantages and disadvantages to gardening indoors using hydroponics. Let’s start off with some of the advantages:

Bigger, Better, Faster

Growing hydroponically allows for bigger, healthier plants that usually grow faster and produce more fruit. When growing indoors and using the proper lighting, most plants will go from seed to flower in as little as 3 months or less.

Harvest fresh fruit and vegetables year round

Since you are growing indoors with the aid of artificial lighting, you can decide when to grow. You are not dependent on the seasons to decide when you can plant and harvest.

Total Environmental Control

Too hot in your room – vent out your light. Too cold - add a heater. Too humid - bring in some fresh air. Indoor gardening allows you to provide optimal conditions for your plants to grow in. Being indoors also helps avoid mold, pests and other adverse creatures.

Ease and Simplicity

Hydroponics is actually derived from Greek meaning “water” and “labor”. Hydroponic systems do all the work for you. Simply set the timer and the system automatically delivers water and nutrients to the plants.

There are also a few disadvantages to gardening indoors:

Cost

Gardening indoors is more expensive than traditional gardening. The initial costs are much more significant and maintenance costs will also be a factor.

Time

Hydroponic gardens will not take up all of your time, but you will need to pay more attention to the system then you would to plants growing outdoors. You will need to check your pH frequently, change out your nutrients once a week and perform general maintenance on your garden to achieve optimal performance.

An air stone helps to provide oxygenate the nutrient solution. This oxygen is extremely beneficial to the root zone and helps to promote fast, healthy growth as well as prevent disease. This is one of the main reasons that plants growing in a hydroponic system grow so much faster than plants in soil. If you are growing in soil you can still reap some of the rewards of oxygen by simply oxygenating your water before applying it to the soil.