My leapord gecko might be sick!! ):

Question
HI,
I have a leopard gecko about 9 months old and he might be sick.
he is sorta just hiding in his shelter, he will eat a cricket if it goes right in
front of him but he will not really follow it. his coloring is also odd. this
morning, he was really dark, but now he is brighter colored. he might be
about to shed. he seems really sleepy, and is not exploring like he usually
does. his poops look weird to. he is on a calcium sand substrate in a 20
gallon tank. please help me if you know what to do to make him better.  

Answer
Hi Ryan, I don't think that you should panic just yet. Leopard geckos are primarily nocturnal,although they will wake up in the daytime if food is put in. Other then that, it is quite normal for them to remain inactive, usually sleeping in their hide spot during the day. Leopard geckos are at their most alert and active around 2 o'clock in the morning! The colour change could be related to an upcoming shed (which would also affect his appetite and activity level) or it could be temperature related. Cooler reptiles tend to be darker, turning lighter as they warm up. You didn't happen to mention what type of heat source you are using. The health of reptiles is really dependent on having the proper temperature.It is always a good idea to double check the temperature right on the surface of the substrate where your gecko would be. Your leo should have a "hot spot" of 85 - 90 F in one end of the tank. His poops should consist of a brown portion which is the actual poop and often a whitish portion as well, which is the equivalent of urine. The poops should have a formed shape, if they are really runny or have a lot of mucous around them then you may want to have a vet examine a sample of the faeces. Even captive bred reptiles can pick up intestinal parasites.
The most concerning part of what you told me is the fact that you are using calcium sand. It is not as digestible as the manufacturers claim it is (pet stores usually just repeat what the manufacturers say). It has actually been found to form clumps when/if swallowed and cause impactions. I would really suggest that you remove it and use something like a reptile carpet.