Not sure if you have a test kid problem or not. But one of the things I never realized until this year was that rocks can absorb and release phosphates. The thread below is a great read.. I think Randy also has a link to someone doing a test with just aragonite rock to see how much phos it can absorb.
Did I unlock all the phosphate from 100#s of live rock?
Hi, @Randy Holmes-Farley Several months ago I did a tank clean up. I pulled all the rocks one by one, soaked them in straight vinegar for at least 15-20 minutes, washed, rinsed, and put back into the reef. My question, is it possible that at 2.5ph, the vinegar has unbound phosphate from my...
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