I have a very large tank in it i have a 2 inch fan tailed oscar and 2 pictus catfish 3inchs and a odd ball firetail tetra (these tank mates have been togeter 5 months and no one touches the tetra him and the oscar get along and sleep togeter )weird) anyhow i have a 4 inch blue african zebra that has been sitting in a 55 gallon tank alone for 6 months would it be possible to add him into the other tank with the oscar and catfish? He is friendly and lets me pet his head when i feed him is this a possible tank mate with the other fish? I dont want to put the african zebra in until i find out if anyone thinks this would be a problem...thank you ,ara

Many African fish like a very high pH, unlike most of your South American fish. This is something to bear in mind. If it was me, I wouldn't mix them, I would try and find fish that come from the same part of the world, as your South American fish. Or what you could do is find fish that also like a low pH, clown Loach one good example and they come from Asia.

Thank you so much for the reply i have another question i have a snail dont know what he is but he is huge inch high and inch wide can he be put in the tank with the oscar and the catfish or will be be ate?

When the oscar gets big he may try to eat the snail, he may not manage it but in the process may injure and kill the snail. I would avoid putting them together if i was you