Warning! I put a male one in my tank with an established Mango Plec, they ripped ten bells out of each other! I removed the Bristlenose, fortunately the Mango has grown back her finnage. They can be very territorial, even to Plecs four times their size.
In my opinion these are the best working plecos in the aquarium. I have over 50 different plecos in my numerous tanks, and these do 10 times the cleaning job as any. They are easy to breed also. I have one breeding pair that is of the albino strain. Just one word of advise when buying them: make sure they have been in the pet store tanks for at least a week and are doing good there. These fish have a high tendency to suck on each other in transit. When shipping they put multiple ones in one bag and when they get to the pet store they appear to have sores all over them. The stores usually lose about 1 in 5 that they get. Finally, if you have an algae problem, don't treat for it, buy a Bristle Nose Pleco!
I have kept Ancistrus for many years and the arey the greatest algae eater, but one thing I've noticed is that they are very sensitive to nitrite...over 0,1 ppm they die very easy. So when you start a new aquaria don't buy them as the first fish in the tank, wait until the tank has been cycled.
I have a breeding pair in my 350 liter aquarium, and find that they are always on the go. They mated about three months ago amongst the fourteen pieces of bogwood, and there are now upwards of ten perfect replicas of mum and dad helping to clean up the algae. All in all a wonderful fish to own.
If you want to breed these fish, I found that all you need is some bogwood with some hollows in and, say, one male and three females so he can pick the best. Also I found that a higher temperature of 27°C really helps! Mine are still small and they bred within a matter of months. I feed them cucumber and peas sometimes, also leaving any algae on the glass. It wasn't hard at all to breed these. Follow these guidelines and you should have a pair of breeding Ancistrus!
I bought a 4 cm bristlenose for my new tank. There is no algae, but my bristlenose (Bouncer is his name) circles my tank all the time cleaning the glass. I have never had any algae and don't think I will get any, thanks to Bouncer!