The cage has 1 day lamp
1 heat lamp
1 UV FL
I use Zoo Meds Reptivite with crickets
a Thermostat that dims or non dims lights to temp
Tank has a slow running fountain
and the tank is sprayed several times a day
iftwod with 4 or 5 hanging plants
I have a female in an exact copy of the males tank
and she is doing fine.
REMOVE THE FOUNTAIN!!!!!! Perhaps an internal bacterial infection? How were his droppings? Do you offer anything else besides crickets? Are the crickets gutloaded? Do you offer any D3 supplements? How old is the UVB bulb? Is there anything between the UVB bulb and your cham? The cage was far too small for the male, but your female should be fine in that size of a cage. Did you wash the hanging plants VERY well? He could have been poisoned by fertilizers or pesticides.
If you are up to it, you could do a necropsy and check for a few fundamental health problems like calcified organs or an intestional blockage etc. About all you need is a razor blade and a strong stomach. It's a chance to learn a bit more about the situation. Take photos. I've done a few on other keepers chameleons and a few on my own .