0 PO4

stevenVDB · 2026-07-17T09:49:53-0400

no matter how much po4 + I doses the tanks still reads 0

I dose 0.04 po4 daily on the doser. Outcome stays 0.
I’m testing with Hanna, tried different lot nrs
It’s been ongoing since a month now. Tester is still accurate, I’ve tested it with a buddy’s tank.

My tank is 6 months old.

allof fish · 2026-07-17T09:52:18-0400

Did you start with dry rock? Do you have any algae issues? Dry rock tends to absorb phosphate for awhile in a new tank. How many corals to do you have

stevenVDB · 2026-07-17T10:04:01-0400

Some new cycles (7weeks) dry rock was added 2 months ago.
I have about 20 corals. Some SPS’s are showing STN

allof fish · 2026-07-17T10:22:37-0400

stevenVDB said:
Some new cycles (7weeks) dry rock was added 2 months ago.
I have about 20 corals. Some SPS’s are showing STN

What are your other parameters. What lights do you run and how big is tank. What does your bio load look like. 0 phosphate won’t necessarily cause stn in acros sometimes just dulls them out. Too much phosphate can inhibit growth