Losing some fish

[Snuff]

I have had my 50g up for just about a week, and I have already lost 3 fish, and I have 2 that are not doing so hot. I checked all my levels, ammonia and nitrites at 0, and my nitrates are low, about 20-30. So far I have lost 2 lab. caeruleus and a zebra cobalt. Now I have an afra "yellow top" and a Maylandia estherae that don't look good.

I think that the problem may be the pink guy in this post here. He is very aggresive, do I need to get rid of him? I have an empty (cycled) 30 g I could stick him into until I can get him to the lfs, should I do this? Or could it be that something else is causing it? I single him out because he seems to be the only one really showing much aggression.

Please help, it's really hard seeing these guys go.

 

[vantgE]

So your pretty sure it's agresion?

 

[Snuff]

On some of the fish, I think. I don't know what else it could be. The lab. caeruleus didn't look all that healthy once I got them home, so I can excuse that. But these others seemed perfectly healthy. I was at the lfs yesterday, and bought another Maylandia estherae, and it was fine when I got it home, and now it just lays on the sand breathing really hard. I don't know what's happening.

 

[vantgE]

Ha, i know i'm useless but it's always good to o a big water change and, try moveing that fish see if it helps any, if it's him you could rearange the tank and retry otherwise you probally gotta bring him back

 

[totalbolshevik]

Don't change too much water at once, I made that mistake a while ago and I will never forget it. Ended up re-cycling my tank and lost quite a few fish in the process. What are your temp and pH?

 

[Snuff]

Temp is right at 80. PH is 7.8.

I moved the one that I think is the problem to my empty 30g. I am gonna see how the other fish do now that he is gone, and probably take him back to the lfs this week some time. If I take it back, I am wondering if I should get another or not. I didn't think they were supposed to be this aggressive, maybe I just got a bad one.

 

[vantgE]

i'd lower the water tempature to about 7.5, and I think you should try him in the tank again if you can move around the rocks,

He had claimed a territory right?
or was he searching the whole tank trying to attack others?

 

[Snuff]

Yeah, he pretty much claimed the whole tank as his. There was one cave in particular, but he would come out and just go looking for trouble.

Oh, and the estherae that I just bought yesterday, I found it dead earlier. It sucks because she was very pretty.

Lower the temperature to 7.5? Do you mean the pH to 7.5, or the temp to 75?