My mbuna's have gone a little wild. Help please?

Hi guys,

I've got a 55 gallon mbuna tank that has been running for a couple months now. I had a stock of 2 yellow labs, 2 socolofi, 2 red zebra and 1 yellow fin acei. All are still juvenile.

One of my zebras is the largest fish in the tank at about 3 to 3 1/2 inches. Recently he harassed the other smaller zebra to the point that it stopped coming to feedings and eventually died. There was little to no other active aggression in my tank.

I really like my zebra, and would like to have 3 total. So I went and bought 2 more recently, trying to get females. I am fairly certain that one of them I got is a female, and the other is likely a male. They are both smaller than the large male I still have. I also recently added another yellow lab.

Since I added these three fish, it seems the aggression level in my tank has gone way up. The other two yellow labs constantly harass and chase the new lab, as do all three zebras... and the large zebra chases and harasses the two new zebras.

The new lab spends most of it's day laying against the glass at one of the top corners of the tank, trying to avoid drawing attention to itself, and the two new zebras spend a lot of the day hiding behind the intakes of my two Emperor 400's. All fish still come out for feeding, but I'm afraid I'm going to watch my new yellow lab slowly die. The two new zebras are handling the aggression much better, but still spend most of their day behind those filter intakes.

Since I've added those three new fish, I've also noticed that the socolofi chase other fish more, and even the two labs I've had in the tank since day one chase each other some, and that never happened before.

I feel like I've really thrown off the balance in my tank and I'm not sure what to do. I did do some rock re-arranging before I added these fish, although it wasn't extensive. I really want to be able to successfully add new fish because I'm only at about half or so of the stock I want to have in this tank.

How do I fix this situation? And how do I add new fish without this happening?

Thanks!

Thanks, I'll do that next time. Any ideas on how I fix the current situation? I could live with taking the new yellow lab back to the lfs, as he seems the most distressed. But I'd really like to keep the two new red zebras, but I hate that they hide in the upper part of the tank behind the filter intakes most of the time. I like my fish to swim, dart in and around rocks, normal mbuna stuff. Thats what all my fish did before I caused this uproar in my tank.

Yeah there's quite a bit of rock in the tank. I think I'll try and do a major rockwork change. Substrate needs a good cleaning anyhow. Maybe that will shake things up enough to allow the new fish to settle in some.

Well, I completely emptied my tank of rock (60-70 lbs worth), cleaned the sand (as well as I could) and completely re-did my rock-work. Added a couple new tall artificial plants to help break things up. Today, things are much better. Although the new lab I added is still a bit on the outs, the new zebras seem to have been accepted by ole big daddy zebra now. Thanks a bunch for the advice everyone. I seem to have re-established some equalibrium.