what the crap! is this eating my acroporas?!

totally forgot about that.. I bet thats it. I started letting the water sit up to a week before I needed it in the 30g plastic bucket. I used to mix and use same day.

 

I have water in my container’s sitting for weeks sometimes – as long as they stay covered to keep the dirt out its all good. But some plastics can and do leech phosphates and this is something we should all test for. If this turns out to be the culprit than good for you – easy fix !!