I have decided to swap my 8 tiger barbs for some other fish. Lately they have been getting more aggressive toward the other fish in the tank, especially fish smaller than them. Looking back now i can attribute a few fish deaths to them. I put a swordtail in the other night after she dropped fry in the smaller tank (which she appears to have eaten) and from the second I put her in they attacked her viciously. I had to put food in the tank just to get them to leave her alone for a while. They also gobble up most of the food leaving little for the other fish which means I have to over feed. I don't really want to get rid of them because I like them so much but I want a peaceful community tank and I'm not getting that at the moment with them in it. At the moment I have the 8 barbs, 4 swordtails and 1 Molly - I have to update my signature...

Any suggestions to what I can add? I'm thinking 2 gouramis (male and female pair), pair of angels, a rainbow shark and an algae eater at least. Other suggestions? The tank is the 45 gal/170l pentagonal tank.

__________________
45g pentagonal
4 Swordtails, 2 dwarf Gouramis, 5 Mollies, 1 Rainbow Shark, 6 Molly fry 6 zebra danios

88 gal Malawi tank
4 Yellow labs, 1 Baenshi, 2 Borleyis, 3 Trewavas, 2 Livingstonis, 1 Venustus, 2 Green Terrors

The angels are cichlids and stand a good chance of being just as aggressive as the barbs, plus they can get as big as barbs. Not sure about the rainbow shark but he might as well. You should Google a profile on the shark and read up on him.

Algae eaters of the Chinese or Siamese varieties are not good for a tropical tank. #1 they are not true algae eaters, they are omnivores, #2 they get big (4" or more), and #3 when they get big they get mean and start killing things to make room for themselves. Plecos are better as algae eaters but do your research, as they can get big as well (common plecos can get up to 24" long). My preferred variety is a rubber-lip pleco, as it is fine on its own, only gets up to 4", is very commonly available, and is docile. Only downside to plecos is they need driftwood to rasp on as part of their diet and make a lair under.

With swordtails and a molly, I would suggest adding a school of zebra danios or bloodfin tetras. Both fish are schooling fish so they do better in quantities of 6-10, but are strong and fast fish and are also mildly aggressive like the swords so there will be lots of chasing but mainly as entertainment and not malicious like the barbs. For a cleanup crew I would suggest a few bigger shrimp like ghost or Amano shrimp and a Nerite snail or two.

Just my preferences though...

__________________
Officially fishless until after the move....tune in later for details!

From my experience the rainbow shark, if the only shark in the tank will leave the others alone if they leave him alone. I have watch mine run 6 tiger barbs around the tank to the point that all of them were hiddden behind the intake tube lol. Needless to say they dont go pissing around in his cave anymore. Everything else Gizmo said is good advice to follow...

Platies and serpae tetras do well with mollies and swordtails.
I have 4 different types of platies. They are beautiful and very peaceful and colorful.
The serpae tetras are schooling fish and nice looking. I currently have
3 of those and they are fine with each other and the other fish in the tank.