i use arrow head im my reef i havent had any problems yet. and yes its RO water. i have a 7 gallon tank it not worth it for me to buy an RO unit and have it sit there.

maybe run some rowaphos or phosban for a couple days, to deal with any phosphates that might be in the water? And then just wait?

I don't seem to have phosphate in my water. strangely. I got a test and tested the water 3 days ago and it was just at 0.25 ppm.

I did a 20% water change yesterday morning. but the sand and rock still turns brown after a couple of hours of light. :sad:
will do another one in a couple of days.

test kits don't test organic phosphate, only inorganic, so it's useless to test for it. 0.25ppm of inorganic phosphate isn't a clear picture of what the organic phosphates are at. Organic phosphates are the nutrients used by algae, not inorganic. And even if you could test for organic phosphate, the algae could be eating it as fast as it's entering the water (fia feeding or liverock die off) to make testing for it difficult.

you can read up on it here:
http://reefkeeping.com/issues/2006-09/rhf/index.php

Water changes can only do so much for dealing with any nutrient problem. Even if the algae dies from changing some of the water, some of it's leftover to provide nutrients for yet another algae problem. It took a whole month to straighten out my tank's algae problem.

:eek: who knew

thanks for the link. that was rather educational for me. hahaha am I glad I got that test :rolleyes:

yeah mine's a useless paperweight now too :biggrin: