Jim Morcombe wrote:

I'd recommend a Bristlenose.

They are fun to watch, clean the glass and the decorations, get on with
virtually any other fish and don't grow too big.

Jim

Jim is right Bristlenoses will not attach your fish like most other
plecos. What about an apple snail - they will only reproduce if they
have a male or female counterpart - they are not asexual.

As for algae (or probably diatoms is what you are seeing too) - they are
good for the water. Cleaning it ALL out of the tank only encourages
new algae/diatoms to grow - this is because the nutrients in the water
that they feed off are ever more prominent in the water if you remove all
of them. So only clean the viewing pane.