R/O and Phosphates

[Reefist]

Ok so I'm checking my RO water and my phosphates were registering which I don't like they were zero last time I checked ( couple of months ago I think).
So here's my question what part of the RO removes phosphates the membrane or DI? I do have a TDS meter on it and it reads 30 in and 1 out but it used to say zero. Thanks for any input.
Tom

 

[Vinny Kreyling]

Tom,
They say to replace the sediment & carbon every 6 months, I do go longer because my incoming is always less than 50.
I would change the DI. Remember we can't read PO4 as well as we would like to, the "noise" in the test kits & meters keeps us close but not exact.
I think my meter says + or - .03.

 

[Reefist]

Thanks Vinny yeah I have all three just didnt want to change them if I need a membrane too.
Thanks
Tom

 

[Usernam Invalid]

I would replace the sediment and carbon blocks on RODI unit also membrane and DI if you haven't changed them in a while. I replace my membrane every year or so. DI and carbon block every 6 months. Sediment filter gets changed when I see it start to discolor. If you are still getting a Phosphate reading you could just run a reactor with GFO on your RO storage container.

 

[WallysWorld]

DI gets rid of whatever is left in the water. How are you testing PO4? Remember this is fresh water. I don't think most of the marine kits will work the same with fresh water.