[jasno999]

Well I say they are sort of needed but nto really. What I mean by that is if you have an algae outbreak or are havign trouble maintaining algae or water quality they are good to have to see if PO4 is your problem. Then they are good to have as you try to correct it.

However if you are proactive and make sure to only use RO/DI water in the tank, not over feed and use some PO4 remover in your filtration system you should be ok. I have a test kit and used it to determine the RO water I was using still ahd a elevated PO4 reading. So I decided to add PO4 remover to my filter and since then I have seen lower PO4 levels and now I don't even test for it anymore.