the point of the recirculating system is so that all the plants get the same nut solution, water lvl, ph and you can control everything from 1 res instead of checking up on the 4 individually. I think is mainly a time and maintenance saver. At least that is what I think i understand about it. If they are different strains you'd probably like to fine tune the individual WF's in case some are growing faster than others and what not. I have tried to learn some about the system even though Im just growing 1 plant from a feminized seed in a WF.