Over the passed few weeks I have lost a couple fish. 2 weeks ago I found my flame angel dead next to a rock, today 1 of my blue chromis were acting strange and then this afternoon I found him dead. The other Chromis is acting the same way and I thought we was dead when I couldn't find him, but he reappeared and isn't doing too hot. All the other fish seem to be doing fine and are all very active. I checked my levels and everything is good. Nitrate is a little high at 20ppm, but there isn't excessive algae growth. I did a big water change yesterday and still can't get the Nitrates to 0. Anyone ever seen this? Any advise?
