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.
What kind of growing media can I use?
Refer to the Growing Medium FAQ’s.
What is pH, and how can I test for it?
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.
Should I top-off my reservoir with plain water or nutrient solution?
In the summer or in hot grow rooms, plants, in general, will take up more water than nutrients, thus causing the nutrient solution to become more salty. In the winter time or in cooler grow rooms, the opposite will occur. Nutrient uptake will also be determined by the type of crop being grown e.g., tomatoes are heavier feeders than lettuce. It is extremely important that the grower has both a TDS meter and a pH meter and that regular testing on the nutrient solution is carried out. If the grower notices after a few days that the ppm level in the reservoir is high and the water level has decreased than the grower should top up their reservoir with either plain water or a weak nutrient solution until the optimum ppm level is reached. If the grower has noticed a drop in ppm levels then a full strength nutrient solution should be used to top off the reservoir. Another factor to consider is the source water. You will generally find that if you are not using reverse osmosis water, you will usually have to top-off with plain water, since tap water has a lot of sodium and minerals that increase the ppm levels.
Here is an ideal scenario: Purchase a Reverse Osmosis System, Auto Shut-off Kit and some R.O. Tubing, which can be found in the Water Treatment section of our website, and a ¼” Grommet and a ¼” Float Valve, which can be found in the Plumbing section. Also purchase a Rubbermaid trash can and a couple of cinder blocks from your local hardware store. Hook up the R.O. system and shut-off kit according to the instruction manuals. The float valve that comes with the shut-off kit should be installed in the trash can, which should be placed on the cinder blocks for elevation. Drill a hole close to the bottom of the trash can and insert the grommet. Install the second float valve in your reservoir, a little higher than where you want the water level to be. Then, run a length of R.O. tubing from the grommet to the float valve. Now, turn on your R.O. system and go spend the time you’re going to save doing something fun! After a period of time, both the reservoir and the trash can will be full, and the R.O. system will stop. It will only come on when the levels in either receptacle begin to fall. Once you add nutrients and enhancers to the reservoir, you will find that the PPM level actually drops each day as the plants take up nutrients and the water is replenished through the float valve (this is especially visible with healthy, actively growing plants). You will also find that you use far less pH adjusting solutions due to the improved water quality. You should only have to add small amounts of nutrients and pH adjusting solution every once and a while between reservoir changes. And, you will always have plenty of pure, fresh water available in the trash can.
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.
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.
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 often should I cycle my Ebb and Flow System and for how long?
See "How often should I feed my plants?”
How often should I cycle my Drip System and for how long?
See "How often should I feed my plants?”
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.
What are the advantages and disadvantages to using hydroponics and growing indoors?
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:
Gardening indoors is more expensive than traditional gardening. The initial costs are much more significant and maintenance costs will also be a factor.
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.
How often should you change your reservoir?
We recommend that you change your reservoir once a week. This entails “dumping” your reservoir and re-filling it with fresh water and nutrients. The reason for this is that as the plants feed, the nutrient solution will fall out of balance. Also, bacteria grows at a geometric rate. If you change your solution every week you will decrease the possibility of bacteria becoming a problem. While it is possible to go longer between changes if you are using reverse osmosis water instead of tap water, you still have the bacteria issue to contend with, so unless you are using something to inhibit the bacterial growth, you should still change your reservoir weekly.
What size water pump do I need for a reservoir that hold “x” number of gallons?
The size of your pump doesn’t depend on the size of your reservoir; rather it depends on how far you need to pump your water and how much water you need to pump. You want to avoid overworking your pump, so in choosing the proper pump you will want to choose one with at least 20% more power than need. To find out your appropriate pump size you will need to determine how much water is necessary to fill your tray. If your tray is in the shape of a rectangle or square then you will need to apply the following formula to determine its volume:
Length (ft) x Width (ft) x Average Depth (ft) x 7.5 = ? US gallons
This will give you the total gallons that your tray can hold. It is a good idea to always get a pump that is at least 20% larger than necessary to avoid overworking it.
After you’ve determined your volume requirements you need to find out how far “up” the water needs to be lifted in order to reach the tray. Simply measure the distance between your pump and the entry point in your tray; most systems will have a distance of under 3’. This vertical distance will have an adverse affect on the pump and this affect must be accounted for. In essence, the greater the vertical distance the water must travel, the stronger the pump needs to be. The following chart will show you how vertical distance affects the pumps. Note the loss of power of each pump as the vertical height increases.
Pump Size (GPH)
Height Lifted
What does an air stone do?
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.
What is the difference between the ½” blue and ½” black tubing?
The main difference between the ½” black and ½” blue tubing is the amount of light that is allowed in by the tubing. The black tubing doesn’t allow any light in. This prevents any algae growth from occurring. The blue tubing is semi-transparent and therefore some algae growth may occur. However, since it is semi-transparent, the grower is able to see inside of the tubing to check for clogs or sediment accumulation. The blue tubing can also be used as a water level indicator or “sight tube”.
Why Do I Need a Reverse Osmosis System?
Purified Water for My Plants???
Walk into any hydroponics shop and you will most likely see that they sell Reverse Osmosis water purification systems. You may ask yourself why someone would spend money on a water filter to grow plants. Most people give straight tap or hose water to their house and garden plants and they do just fine. But, what about more prized flowers and fruits? What if you only want give your vegetables the best and most pure ingredients? Most importantly, what if you were interested in pushing your plants to the max and achieving explosive growth? Serious gardeners have long realized how important pure water is to the success of their important crops. After all, water is the root of hydroponics and therefore the most important component to a healthy garden. Water acts like a carrier that bathes your root zone with nutrients, additives, and promoters.
If you look at the top nutrient manufacturer’s feed charts, you will notice a common theme. They all require using 0 PPM (parts per million) water as a starting base for the nutrient solution. Without this ultra pure base, it is much more difficult to dial in the PPM’s of your formula while making sure you have the proper amounts of each component vital to healthy growth. When the feed chart says bring the nutrient solution to 1200 PPM and you are starting with water that is at 500 PPM, what do you do? It is hard to even guess what that 500 PPM is composed of, nonetheless try and adjust for it in the nutrient formula you are trying to perfect.
The first step is to determine how bad your water is and what type of system would be most beneficial to your garden. Free water reports are available from your municipality or water company, although water quality fluctuates greatly throughout an area and over the seasons. Test kits can be ordered online and are quick and affordable. Some hydroponics shops do water testing and there are many labs that can do an analysis. A key indicator of water quality for plants is total hardness as expressed in PPM of calcium and magnesium or in Grains per Gallon (GPG). With too much hardness, the nutrient formula can be thrown out of balance and deficiencies and lockouts can quickly become a major problem. Any water source over 50 PPM of hardness should be purified. This translates to 3 GPG and is considered soft water, which few people have straight from the tap.
Organic gardeners using compost teas or bio-extraction solutions should use purified water. Anyone gardening with living micro-organisms such as beneficial bacteria, fungi and nematodes, mycorrizae, and trichoderma, must have chlorine and contaminant free water in order for those helpful microbes to survive and flourish. Unfortunately, it’s rare someone’s water source is perfect for their prized plants. Letting city water sit out overnight may get rid of some free chlorine but doesn’t affect the chloramines or other contaminants. Water from well or spring sources is often too high in minerals such as calcium, magnesium, sulfur, and iron. This water may be fine to drink but for hydroponics may be too heavy with these minerals and may contribute to nutrient lockup.
Gardeners that start using pure water never go back to untreated water. There are still plenty of people that haul 5 gallon jugs of water to their garden. They will go through these lengths to pamper their plants and make sure they only get the best. If you do the math, a water purification system from a hydroponics shop pays for itself quickly with the money and energy saved hauling water. There are several customized filtration systems available for gardening and hydroponics on the market.
Following is a table that shows the most common contaminants in your water, their sources, and what harmful affects they can have on plants. After looking it over and realizing how many things can do damage to your crop, you may want to grab yourself, and your plants, a nice glass of pure water!