Po4 in fresh made salt water

[Mattl22]

I just tested my clean salt water and found detectable amounts of po4 with red sea test kit
Does this mean I need a new rodi membrane my tds reads 0

 

[Mattl22]

And what's the deal with silicates can they be teasted for and how can I eliminate them
My tank po4 is reading 0.1 same as clean water now I know the test kits suck but at least I know the po4 is present in my clean water so need to fix that

 

[bigbris1]

If you're getting detectable PO4 in your freshly made saltwater, you might want to do some additional testing/research in your choice of salt mix. Also, I would test the water before you added the salt mix to make sure it's the mix.

Then, you may wish to add a drop in filter to you freshly made water with GFO to reduce the amount of PO4 before you add it to the tank. This is what I used to do.