High Phosphate

Mike T IL · Jul 16, 2020

I have a mixing station that has two 50 gallon plastic barrels. First barrel is filled with 6 stage RODI water, 0 TDS.

My corals have started to die. Just got an ICP test results. Sample taken on 7/1 and my PO4 was 0.049. I just tested my water today and my PO4 is 0.54. I can’t figure out where it is coming from. Tested my salt mixing barrel and it had PO4 of 0.47.

I use Aquaforest reef salt.

What could cause high PO4 after creating new batch of Saltwater from RODI water and salt?

Spieg · Jul 16, 2020

My guess is your home test is not accurate.

Mike T IL · Jul 17, 2020

I have used 2 different home tests. I just did a 40% water change last weekend. Now my corals are dying. Before doing the water change I replaced my RODI filters and resin. Also added a second membrane.

tundraguy1106 · Jul 18, 2020

I agree. Get another test kit. Hanna phosphate tester is my go to for phosphates. Most others are unreliable. If it is high, Throw a filter media bag filled with phosguard in your sump to bring it down while you figure out where it’s coming from. I try to keep mine at .03.

What makes you think it’s phosphates? What are your other parameters?