Raft hydroponic gardening systems are “water culture” hydroponic systems. Unlike flood-and-drain and wick systems, no grow media (e.g. rockwool, coconut coir) is used. Instead, plants grow directly in water, enriched with nutrients.
As the name suggests, plants are suspended in a floating material such as polystyrene, with their roots dangling in the nutrient-rich solution below. An air pump bubbles through the water to create an oxygen-rich atmosphere around the plants.(Oxygen is as essential as nutrients in hydroponic gardening.)
Raft hydroponic systems are highly-effective for growing plants like lettuce that thrive on a lot of water. A disadvantage is that they are not suitable for plants that don’t like this level of saturation.
The advantage of raft hydroponics systems is that they are simple and relatively cheap. Almost anyone can build their own system with no special expertise or equipment.
Free plans for raft hydroponics systems include:
A very simple hydroponics system for indoors and for a larger system, how to make a hydroponics garden from a fish tank or PVC tote.