Can you send a picture of his pelvis, back and tail from above?
Sometimes their orbital crests--I think that's the right terminology, the ridge over their eyes--is conformed in such a way to make the eyes look deep set so they appear sunken when they are not. Chameleons also will pull in their eyes when they are being handled or photographed. A picture is often deceptive.
When they are dehydrated the skin loses that plump moist look and has a dry look to it. However, the skin will have that look as they prepare to shed, too.
Looking at the color of the urates is also helpful but not the be all and end all of judgine dehydration.
I like to look at their skin and the way the skin fits over their hips, tail and spine. A dehydrated animal will appear thin in those areas.
His eyes do look a little sunken in but his skin looks great. I wonder if it is just that he has such a pronounced brow so his eyes look sunken in.
Do you and your chameleon a favor and get yourself a MistKing. I bet you've already spent more than the cost of a MistKing with all the things you have tried that are not really working very well. They need the mist to clean their eyes, not just for drinking. They are no trouble at all once you get everything hooked up properly. You might think about getting extra hose. Use reverse osmosis water. If you don't have a reverse osmosis system, just buy water. One or two misters don't use much water. Fill it so that you need to replenish the water every couple of days rather than letting it just stand in the bucket.
You mentioned having hard water. Everything I read on misting systems says to use distilled water - not just bottled water. Regular tap / bottled water will eventually clog up the system.
