kristy, move your gecko back to his old enclosure for now and provide food in water in the same ways that you used to do so. give him about a 10 minute soak in lukewarm water if he will sit still and not stress about it too much to help hydrate him. the fact that he is drinking on his own is good, but soak once today and twice tomorrow if you can and it doesn't seem to stress him too much and mist often. do his eyes look sunken it at all? that is another sign of dehydration.

is there anything in the new enclosure that might have been cleaned with a chemical or might have any foreign material on it? when was the last time he ate crickets and did they come from the same place your normally get them? has he been in contact with anything that your leo was in contact with?

take a fecal sample to your vet and have it tested, and ask specifically for them to look for entamoeba invadens. this is extremely dangerous and fatal in cresteds but can be treated if caught in time. for more info on entamoeba invadens look here: http://www.ciliatus.com/content/inde...=42&Itemid=207. sometimes a healthy gecko will not exhibit signs until they are under some kind of stress, including a new environment--at this time they tend to go downhill quickly.