At the moment, I'm waiting for 3 pairs to replace the 3 pairs that were killed from series of CO2 leaks. The most number of rams I had kept in my 4 feet was 4 pairs.roud: No issues with them. The only problem I have with multiple pairs is that new fish like tetras will have no way to escape their aggression considering they treat new fish as intruders. But I accept the fact that new fish will always be considered intruders. I'm trying to add the characins first before those rams are added or else the rams will end up killing several tetras again.the tank is 5ft long. Thanks joejoe. Anyone else here keep multiple pairs of blue rams in the same tank?