I have a 29 gallon tank with a breeding pair of convicts and two other adult convicts. I wanted to see if there was any type of pleco or algae sucker that I could add that would have a decent chance of surviving. I added a couple of small chinese algae suckers before I introduced the male and while I still had a blue crayfish and neither one of them made it. The lobster is no longer with us and now that I have the male they obviously get aggressive when the fry hatch. After a couple of days I usually take the fry and feed them to the Africans in my other tank to keep the parents from killing the other two convicts. Is there anything I could add to keep the tank clean that will survive? Thanks.