In deep flow technique (DFT) a large volume of water and nutrients recirculates which is costly to disinfect. Mostly there is no disinfection in these type of systems increasing the risk for calamities. Ultrafiltation membrane appears to be a cheaper and a just as efficient equipment.
This was reason for Wageningen UR Greenhouse Horticulutre to test the method for elimination of Fusarium oxysporum. The results were good, the UF membrane eliminated fusarium with more than a factor 1000. The composition of the nutrient solution did not change. However, during long term circulation the iron content should be guarded as iron is bound to chelate and may be blocked by the membrane.
The UF method may be a good addition for systems with large quantities of water in recirculation and traditional system may be too expensive.
The UF membrane, a small handy apparatus, have been used the last season at Kreling Chrysanthemums in the Bommelerwaard and will be supplied to the market by Aqua D&S and Fase Advies from IJzendoorn.