Ammonia woes...

[Saltee]

Hoping the group can help...

I've got a 92gal reef tank going. This is my first marine aquarium and I've only been at it a few months now. At this point, it is still lightly stocked (three fish, five corals, and a handful of cleaners). I seem to have most of my water parameters under control... well, all except one -- ammonia -- and no matter what, I can't seem to beat it.

I've always had some low level present in the tank (i.e., never a true 0 reading, but less than the next step up on the stupid color scale). The LFS recommended more frequent water changes, so I went from 25gal change once a month, to 25gal every other week. Well the ammonia actually seemed to go up and I noticed that it seems to peak after water changes, which got me thinking, "how much ammonia is in the *NEW* water I've been adding?" Turns out the new water has about 0.5mg/L ammonia! 8O

This is city water, run through a 4stage RO/DI system (Kent Marine Maxxima HiS 60gpd). Being a newbie, I guess I had fallen into the "RODI removes all problems" trap. So, at long last, my question....

What more can I do to purify the new water I'm using for water changes?

Thanks in advance for your help.

 

[fishfreek]

First thing to do is test your tap water before the RO. Then test the RO water and then finally test some freshly made saltwater.

I suspect you might have a test kit that is reporting false positive ammonia readings.

What salt mix are you using. There should be no trace of ammonia comming out of your RO unit.