Deep Water Culture Hydroponic System, 11 Cup

A hydroponic method where the roots hang directly in nutrient solution instead of in a flowing stream. An air pump keeps the water oxygenated. It is the simplest hydroponic method there is, because nothing has to circulate.

Roots need oxygen as well as water. In still water they run out and the plant drowns. The air pump bubbles air through the solution and keeps enough oxygen dissolved for the roots to keep working.

The basin and its lid, an air pump, a silicone hose, a buoy and buoy deck, 11 planting baskets, 11 planting sponges and a pair of tweezers. Seeds and nutrient solution are not included.

Eleven at a time, one per basket.

Moving a germinated seedling into a planting sponge without tearing the root. It is fiddly with fingers and easy with tweezers.

In NFT a pump moves a thin film of solution along a channel past the roots. Here nothing moves except air bubbles. NFT scales to far more plants; DWC is simpler, has less to go wrong and copes better when the power drops.

Less than you would fear. The solution stays where it is and the roots stay wet. What you lose is aeration, so a short outage is fine and a long one in warm weather is worth reacting to. An NFT system, by contrast, drains as soon as its pump stops.

It is the one we would point a beginner at. There is no flow to balance, no channel to block and very little to set up. The skills you learn here transfer directly to a larger NFT system later.

Lettuce, herbs, rocket, spinach and other leafy crops. Eleven sites is a household supply of salad and herbs rather than a vegetable garden.

Only if it is somewhere without enough daylight. A bright windowsill can be enough in summer. Indoors in winter, or in a room without a good window, you will need a light.

A general hydroponic nutrient suited to leafy greens. It is not included. Mix it to the dilution on the bottle rather than by eye, because too strong causes more harm than too weak.

Every two to three weeks is usual, topping up with plain water in between as the level drops. If growth stalls or the leaves go pale, a full change is the first thing to try.

The buoy. It sits through a hole in the deck and rises and falls with the solution, so you can read the level at a glance without opening the lid and disturbing the plants.

It helps a great deal. Most leafy crops prefer somewhere around 5.5 to 6.5. A cheap pH pen and a bottle of pH down turn guesswork into something you can control.

Nine times out of ten the blue valve has been fitted the wrong way round. Turn it over so the pump is pushing air into the solution rather than trying to draw from it. If the bubbles are weak rather than absent, check the air stone is not blocked.

Keep light off the water, which the kit is designed to do: the basin cover and the baskets block light. The mistake to avoid is leaving the lid off or running it in strong direct sun with a gap open.

There is a quiet hum from the air pump and the sound of bubbling. It is comparable to a small aquarium. Sitting the pump on something soft rather than a hard surface cuts the buzz noticeably.

Very little. It is one small air pump running continuously. If you add a grow light, that will use considerably more than the pump.

For a week or so, if the basin is full when you leave. It has no channel to run dry, so it is more forgiving than an NFT system, but plants still drink and the level still falls.

Empty it, rinse the basin, and pull the hose and air stone off to flush them through. Skip the detergent: anything left behind ends up in the next solution.

Carefully and not far. It is a tub of water with plants suspended in it, so it is heavy when full and the roots do not enjoy being sloshed about. Decide where it lives before you fill it.

Yes, they are the growing medium and are used up with each crop. Eleven come with the kit, which covers your first planting.

You can, but most people germinate separately and move the seedling across once it has a root, which is what the tweezers are for. Our seed starter trays are made for that first stage.

Growers generally report faster growth than the same crop in soil, because the roots get water, nutrients and oxygen without having to search for them. How much faster depends on the crop, the light and the solution, so we would rather not put a multiplier on it.

It is a single tub with a lid, so a worktop, a windowsill deep enough to take it, or a shelf. Leave headroom for the plants and somewhere beside it for the air pump.

Yes, in a sheltered spot. Keep it out of the strongest direct sun, which warms the solution and encourages algae wherever light gets in, and remember the pump needs power.

Cool is better than warm. Warm solution holds less dissolved oxygen and suits root problems, which is another reason to keep it out of direct sun rather than in it.

The basin cover and baskets are made to block light, which is what the supplier specifies about the material. We do not have a food contact certification to publish for it, so rather than imply one we would say ask us and we will put the question to the supplier.

Across Europe in 5 to 7 days after a 24 to 48 hour handling time. Free over EUR 50, otherwise EUR 22. Express delivery is available at checkout.

Tell us and we will replace it. Check the contents against the list when it arrives rather than at planting time.