unclenedsfishfactory.com

Specs:
90 gallons
12 cichlids (various kinds) in tank for 2.5 months
8 cichlids (various kinds) added 3 weeks ago
21 total fish

They all were getting along very nicely. However, in the past three days they started getting aggressive - to the point that when I checked on them this morning, one moz. zebra had lost almost all his fins before I rescued him (too late unfortunately). Just about all the other fish were harrassing him and snipping at him.

Many of them seem a little more aggressive than normal, and the atmosphere of the tank has gone from happy to "tense."

Excuse my ignorance - I'm new to this and just learning to care for cichlids - but what gives? Any possible suggestions for why things have gotten chippy?

90 gals and 21 fish seems to be below the level of crowding to keep agression down. The dominant male(s) have probably set up territories and now are defending them.

Also, perhaps there is some spawing going on or about to....and this always increases the tension in the tank.

My advice would be to get more cichlids in there....and be careful about what you put in the same tank.

I would turn the heat down to 71 degrees F.
Also feed the fish more and/or more often.
It's not a bad idea to add more fish,
also maybe add more hiding spaces.

It's usually a good idea
to have back-up "jail" or "hospital" space.
We sell a 2, 5, or 10 gallon tank with a heater and a filter for $50