There are four types of hydroponics we use at Not Just Pots – we use them for growing different types of things. Currently 2 of our 3 polytunnels are used for hydroponics of one sort or another.
Hydroponics at the consumer level is still a relatively new thing in the UK – so new that it’s fairly likely when you shop for the systems and supplies people will assume you’re growing weed not veg!
So here’s a quick roundup of the systems and what we use them for:
Seedlings for all these systems are propagated in wool cubes until they’ve sprouted and developed a good root structure.
(Nutrient Film Technique)
This is the kind of hydroponic system most people think of when they think about hydroponics. NFT systems have a constant flow of nutrient solution. The nutrient solution is pumped into the growing tray and flows over the roots of the plants, and then drains back into the reservoir.
There is usually no growing medium used other than air, which saves the expense of replacing the growing medium after every crop. Normally the plant is supported in a small plastic basket with the roots dangling into the nutrient solution.
Most of our lettuce grows in this and in the summer we can harvest one a day.
The aeroponic system is probably the most high-tech type of hydroponic gardening. Like the NFT system above, the growing medium is primarily air. The roots hang in the air and are misted with nutrient solution. The misting is usually done every few minutes in some systems or continuously in others like ours. Because the roots are exposed to the
air like the NFT system, the roots will dry out rapidly if the misting cycles are interrupted so keeping an eye on these is vital.
We use this for fast growing herbs like Dill, Basil, Cilantro and Parsley.
The water culture system is the simplest of all active hydroponic systems. There are a few different ways to do this
- The plants slot into foam mats that float directly on the nutrient solution. An air pump supplies air to a series of air stones that bubbles in the nutrientsolution and supplies oxygen to the roots of the plants.
- The other type is a cascade system which is pumped and the falling water oxygenates itself. Air is incredibly important for roots – so if the roots are in water it must be well oxygenated.
Most of the time we grow our watercress in the cascade system – it thrives and keeps us in lovely peppery leaves.
On the floating mats this year we grew rocket (arugula), pak choi and spinach. We have grown herbs and leaf lettuce quite well this way too. If you want to build your own Water Culture system, there are details in this article https://notjustpots.wordpress.com/2017/07/20/building-a-watercressinator/
Flood and Drain
The Ebb and Flow system works by temporarily flooding the grow vessel with nutrient solution and then draining the solution back into the reservoir. This action is normally done with a submerged pump that is connected to a timer.
When the timer turns the pump on, nutrient solution is pumped into the grow tray or pots. When the timer shuts the pump off the nutrient solution flows back into the reservoir. The Timer is set to come on several times a day, depending on the size and type of plants, temperature and humidity and the type of growing medium used.
We use large Flood and Drain pots to grow Tomatoes, Tomatillos and Peppers
As for the nutrients we use – we only use them in the NFT and Aeroponics – the rest are plain water. As we come to the end of a growing cycle, we flush the plants with plain water.
As this is a water based growing system, the plants need to be fed nutrients to grow. Each type of plant has specific nutrient requirements, that is why we use several systems, so that we can put plants with similar tastes in nutrients together so that they grow well.
As we come to the end of a growing cycle, we flush the plants with plain water.