What were the chams in before? I don't keep big chams, but my uneducated opinion is that it's not near tall enough and they could use the bottom open...i.e., a full screen enclosure instead of a tank/cage top. I think that setup would work OK for young chams; I wouldn't pitch it (but then I never pitch anything...how many tanks/filters/heaters do I have sitting around?), but I would get something bigger/airier ASAP.