Floating Raft
A deep water culture method where plants sit in holes in a floating foam or plastic raft while roots hang into an aerated nutrient solution below.
Floating raft ensures that plants are always at the correct water level, providing plants with more consistent access to water and nutrients. This method is great for fast-growing greens.
It is less complex from a mechanical perspective than several of the other methods, considering pumps, pipes and other moving parts with NFT, Ebb and Flow and drop systems.
Floating raft setups often have larger water volumes, which also helps stabalize temperature and nutrient conditions.
Note that you still need aeration, so its not completely without mechanical parts.
Troubleshooting
Roots turn brown or slimy.
Increase aeration, lower water temperature, clean the reservoir, and check for root disease.
Plants tip or fall through holes.
Use correctly sized net pots or collars and match hole size to crop size.
Maintenance
- Keep the nutrient solution aerated and cool.
- Clean rafts between crops to reduce algae and pathogen buildup.
- Check that plant crowns stay dry and above the waterline.
Make It Yourself
- Prepare a watertight reservoir or shallow tank with a lid or floating raft material.
- Cut holes for net pots at the spacing needed by the crop.
- Fill the reservoir with nutrient solution and add aeration using an air pump and air stones.
- Place seedlings in net pots so roots can reach the solution while crowns remain above the raft.
Cost
- 50 - 600 NZD
Power Consumption
- 3 - 100 W
Variants
- Static raft with aeration: A simple raft floats on an aerated reservoir with no active water circulation.
- Recirculating raft bed: Nutrient solution circulates between one or more raft beds and a shared reservoir or filtration zone.
Cultivars
- Lettuce and leafy greens: excellent
- Spinach: very good
- Rocket: very good
- Watercress: excellent
- Basil: very good
Images
- diagramUrl: /media/knowledge-base/dev/methods/method_raft_reduced.png