My ro/di unit and phosphates

dannyab84 · Dec 1, 2013

So I've been having algae problems for a bit now and finally think I found the cause. My ro/di units water is reading .5 phosphates from my seachem test kit. I tested it after letting it run for a few mins then in a glass vial. The ro/di unit is only maybe a month and a half old and I had it tested for tds when I first got it. I had no problem with the tds then. However, I will bring my water to my local fish store in the next few days and have it tested again. Is there something I should do like get a liquid phosphate remover and add it to my water before putting it in my tank? Thanks a lot for any help guys!

Oh and it's a 50 GPD coralife ro/di

AZDesertRat · Dec 2, 2013

You cannot accurately test phosphates in ultrapure water. The test kits are meaningless and intended for salt or fresh water, not RO/DI or distilled.
If you are registering 0 TDS with a reliable handheld temperature compensated TDS meter you should be good. You can't really own a RO/DI without also having a good TDS meter like the HM Digital TDS-4TM, AP-1 or COM-100, its you only reliable affordable tool other than an expensive resistivity or conductivity meter and is very accurate.

dannyab84 · Dec 2, 2013

Thanks for your reply! And yeah that came to thought when testing the water. Then do you have an advice when it comes to phosphates? I just checked my tank water and it was at a .7 with a lot of algae and canyo following it. I do have a GFO reactor and some kalk coming from brs that I bought with this weekends sale. I do however, already have gfo in my tank just not in a reactor. But my main concern is really where its coming from. I feed only every 3 days and run a 150 reef octo on my 55 gallon tank. I have not used any additives and have a uv in the sump. Any tips at all would be fantastic!