People get freaked out about putting natives with tropicals, bbut with sunfish atleast there is no reason you can, other than temprement. They do fine at low tropical, or room temps year round, and do not need a cool down unless you want to breed. Temprement does need to be considered, but just like cichlids sunfish are individuals so it just depends. It might work, it may not. I say go for it, but with a back up plan in the case it doesnt. Putting the native fish back is not a back up plan. Sunfish are great though, youll like them.