Example Types of growing methods used in Hydroponics

Passive Systems This method of growing hydroponically is very easy and is an ideal introduction to growing without soil. It also needs very little equipment, yet should still allow you to grow plants better than simply in soil. The method you can see in the picture is the way I will be trying to passively grow tomatoes and cucumbers this year (2006), as we currently don't have a greenhouse with electric power this is an ideal time to try this method.

The system is set up by filling up a pot with some medium for the plant to grow in, rather than soil this could be either perlite or clay pebbles which are both popular neutral growing mediums and are easy to purchase in garden centres. The medium is rinsed thoroughly before being placed into the growing pot. If you are using perlite make sure you rinse this in a well ventilated area as dry perlite is very dusty, also make sure the pot you are using has drainage holes in the bottom.

The plant is then placed into the medium like you would plant a normal plant into soil. I have grown my plants from seed and grown them entirely in rockwool cubes so I can just place the cube with the plant straight into the pot.

This also means no mess, apart from the perlite which can make the area look like it's just snowed and it also gets very sticky when wet.

The pot and plant is then placed into a pot saucer tall enough for quite a bit of nutrient solution(Water and Nutrients) to sit in, the nutrients are then used to water the plant as you would water a normal plant in a pot so that the nutrients flow through the medium into the saucer at the bottom. This process will probably only need to be done every few days when the plant is small but might need to be done once or maybe twice a day if it's warm weather or the plant is growing large and using lot's of nutrients.

I will be growing quite a bit with this system this year (2006) and will keep my web site updated with photos and any progress so keep checking back.

Aeroponic Systems For quite a while it has been agreed by experts that a properly working aeroponic system is pretty much the most effective way of growing plants without soil. The way an aeroponic system works is by supplying the root zone of the plants with a fine mist of liquid nutrients rather than just a continuous flow of liquid, this not only fulfills the plants nutrients needs but also gives the plant a large amount of oxygen within the nutrients which is an ideal situation to be in.

The fine mist in a small system can be supplied by a spinning nozzle which is simply attached to a standard hydroponic nutrient pump outlet within a nutrient container. The plants are then suspended in baskets or just loose above the mist so that the roots dangle into the nutrient spray.

One of the good things about a small system like this is that you can easily see all the fast root growth as it happens by carefully lifting the plants out of the nutrient mist.

The biggest problem with an aeroponic system is the upkeep necessary to keep the fine mist system working correctly. For example blocked nozzles will instantly stop the system from working correctly and starve the plants of the necessary oxygen and nutrients they need.

Aeroponic systems are currently in the early days of development and I'm not sure at the moment whether these systems will prove reliable enough for continuous use, but I am going to give one a go this year (2006) by trialling an aeroponic propagator I have purchased. Early results are very very encouraging, please keep visiting my 2006 web pages for photos.

Also if you would like to see a large scale aeroponic system in action you might like to take a trip to Epcot at Walt Disney World in Florida, In the Land area of the park you can see a large scale system in action for yourself which supplies food to all the Hotels and Restaurants around the Walt Disney resort. If your not planning a visit soon though have a look at my Out and About Gallery where you can find some photo's I have taken from a previous visit there, There are also photo's of the other systems they have there such as NFT systems etc.

NFT (Nutrient Film Technique) This method is the simplest of all ways of growing hydroponically and is the one I use most in my own growing. This system involves allowing a shallow film of nutrient solution (This is Water with nutrients added) to flow past the roots of your plants. The solution is usually pumped from a holding tank to the end of channels where it then flows over the roots before falling back into the holding tank. This process is usually run continuously throughout the day, It is not usually necessary to run the process through the night.

A setup like the one shown above can be made more advanced by adding an automatic topup system, This will allow the Holding tank to fill itself up automatically when it starts to go empty.
An examply of this can be seen on my Greenhouse pages, Where one of my greenhouses is fitted with a automatic topup system from a pre-filled water butt.

A Spreader matt is usually placed on the channel floor to allow an equal distribution of nutrients across the floor of the channel.

Plants can be placed into the channel at any state of growth as long as a good healthy roots are present, If they are the plant can simply be placed into the channel's flow of nutrients.

Dripper Feed systems The dripper feed system or drip irrigation system makes it easy to treat each plant individually with regards to the amount of nutrient solution each receives. The nutrient solution is pumped up from the holding tank along pipes to drippers, These hang over the plants or are inserted into plant pots or blocks of rockwool as in the animation opposite. The dripper itself is fitted to limit the flow from the pipe to the plant to just a mere drip. The plant will take what it needs and any excess solution is allowed to drain back into the holding tank ready for re-use. Like the NFT system it is not necessary to run the pump throughout the night.

I have tried this system out myself during the 2002 season and although it worked succesfully I am now using the tank and pump for a plain NFT setup. Partly because I didn't see any increase in production over growing with the NFT Method and Partly because of the extra work necessary in setting the system up and keeping it working (ie. the drippers kept getting blocked for me).

Water culture system In water culture systems the plants are placed such that their leaves are bathed in the nutrient solution within the holding tank. In a floating ( sometimes called a 'Raceway system') like the one opposite the nutrient holding tank is actually the growing bed. The plants themselves are placed into holes on floating styrofoam boards with their roots dangling into the nutrient solution. The solution itself rather than being pumped around as in the other systems, Is oxygenated and moved around the plant roots by an aquarium type air pump attached to a perforated tube at the bottom of the holding tank, Which continuously blows air bubbles into the nutrient solution. Plants which seem to enjoy living in this system are leafy plants such as Luttuce, Spinach, Chard etc. Unlike the other systems here the pump must be run continously to oxygenate the nutrients.

I am regularly using this system each year now successfully along side my main hydroponics systems to grow batches of lettuces. To see what my water culture system looks like have a look at the Greenhouse No 2 page.

Ebb & Flood systems This method is more complicated, It is also a system which I have not tried for real yet. But I've detailed it here for completeness. It involves flooding your plant table with nutrient solution for a set time. The nutrient solution is then allowed to Ebb away back into the holding tank. Now a delay occurs and the routine begins again. This system requires more equipment than NFT, Including a Timer and something to allow the Ebb to occur. This system is sometimes used where a more decorative system is needed, As pebbles can be placed between the plants on the table.