As fish are added and the bio-filter comes up, we are designing a new seedling bed for our new seedling house. Hopefully the design will keep our seedlings moist and well fed until they are transplanted to the rafts.
The water is the same nutrient rich stream supplied to the grow-bed. For the grow-bed we are using what’s called “deep water culture,” with plant rafts floating on about fifteen inches of water. The deep beds help keep the lettuce from bolting due to summer heat. However, the seedlings need to stay wet, but not too wet. Rather than use a timer to flood and dry (ebb and flow) or a drip system, we decided to experiment with an extension of our existing gravity fed, constant flow design. The seedlings will be in Rockwool starter plugs. Sheets of the plugs will lie on the table wicking up water. By adjusting the water height we hope to keep the seedlings at just the right moisture.