So I made a post a while back about some aggressive kribensis, which required the purchase of a 65 gallon tank. It's since been cycled (thanks to some media from my other tank) and had additions.

I added the other kribensis from my 29 gallon and added 10 tiger barbs (thank you posters for the advice), and a red tail shark.

I had worries for a while since the red tail didn't seem to be eating. After a while of never seeing it do anything but hide (it's very tiny compared to the two very territorial kribensis), I noticed a bulging stomach. Apparently red tail sharks eat more algae than any oto cat I've ever seen. The mouth is like a machine gun as it methodically eats all budding algae from the tank walls and decorations.

Aside from that, the red tail has worked its way into the school of tiger barbs. The tiger barbs not only worked as a dither for the red tail, but he became a part of their school with his current size. As they worked out the hierarchy in the school, he was involved (pretty low on the totem pole right now), and hides amongst them to avoid the larger kribensis.

Interesting behaviour. Just thought I'd share. And needless to say, algae has become a non-problem.

As a footnote, my red tail is very docile in this tank because of its particularly aggressive tankmates. At the LFS, it was VERY aggressive, which is why I picked it, knowing where it would go.

__________________
Fish can be cute. Just watch a bunch of happy corys in the same tank together. They're like little zoidbergs, but without the awkwardness or ineptitude... well maybe a little awkwardness and ineptitude.

Sound like your krib are breading?? Mine are very piecefull in the community tank....

I've read online and in books Red tailed sharks can be very docile in certain situations but are also a favorite in the cichlid world because they can be aggressive enough to hold their own in a cichlid tank. My red tailed shark in my community tank is very docile, he has his cave and as you said, almost never eats flake but instead picks in the gravel for food. i got him sinking shrimp pellets and he seems to like them. He very rarely has a run in with a tiger barb but it is never anything harmful to either fish, he mostly cruises the tank on his own feeding on the bottom. They are in the carp family if you didn't know.

__________________
55 gallon FW community
20 gallon Goldfish
10 gallon firebelly toad

I agree about red tail shark behaviour... my red tail shark has never shown any aggressive behaviour, but when threatened by the cichlids, he stands guard very well and never budges, except to avoid getting nipped. [EDIT: He has not shown any aggressive behaviour in my tank. In the store he was VERY aggressive against other red tails, but that is to be expected] All the danios, barbs, and tetras I've ever had (except for neon tetras) have shown much more aggressive behaviour than this one. He spends most of his time cleaning up algae, if not resting close to a (fake) leaf for cover or hovering in the middle of the tiger barb school.

As far as my kribensis, I have two males. So I know it's not a breeding thing. I think I just got two unusually aggressive ones. The whole reason I settled for the less colorful males was in hopes that they would be more docile, but that was not the case.

__________________
Fish can be cute. Just watch a bunch of happy corys in the same tank together. They're like little zoidbergs, but without the awkwardness or ineptitude... well maybe a little awkwardness and ineptitude.