Sometimes, in life, you have to ask yourself if you are part of the problem or the solution. I thinks its clear at this point where this guy is.
Large cichlids:
Do you have full-spectrum lighting on him? Full spectrum UVB can be provided through ballasted bulbs, or those Zoo-Med florescent bulbs, get the 8.0 version. He needs this, or his bones are going to wither away, and he'll die. Oh yeah, sorry, you already knew that.
If you have a 75, why is he in the 29? Is this the same tank that the other lizards died in? Why do you keep getting more pets if you can't keep others alive?
Large cichlids:
Do you have full-spectrum lighting on him? Full spectrum UVB can be provided through ballasted bulbs, or those Zoo-Med florescent bulbs, get the 8.0 version. He needs this, or his bones are going to wither away, and he'll die. Oh yeah, sorry, you already knew that.
If you have a 75, why is he in the 29? Is this the same tank that the other lizards died in? Why do you keep getting more pets if you can't keep others alive?