Help with crabitat

Question
I bought my daughter a crab on the boardwalk at Ocean City NJ and I think it is a strawberry crab.  Really big and reddish. $145 later (ahhhh!), I still can't get the temp or humidity right.  Our house is central air conditioned and it is hard to keep the air in the tank moist.  I have a 5 1/2 gallon tank (probably need a 10 gallon) and I have sand/coconut fiber bedding (only about 1 1/2 inches deep).  I think I need a bigger tank, deeper bedding (How deep?) and one more crab.  My under tank heater is mounted to the side of the tank since the package said if the substrate is sand, the heater could crack the glass if under mounted.  It only heats to about 70-72 degrees so I bought a small clamp lamp with a blue day bulb and a red night bulb.  But when I try to use the lamp, it over heats the tank to about 90 and dries it out.  Also, the tank I have has a mesh top which I cover with plastic wrap (except for a corner).  The crab was active the first few nights and now he just sits next to the heater and hunkers down.  I picked him up and placed him on his food last night, and he walked back to the same spot after about 10 minutes.  Any tips on where to get a glass tank with a glass or plexi lid? Petsmart didn't seem to have any with glass lids, only fish tank lids.  And if I do switch to a 10 gallon tank, what kind of tank heater works best? How deep should the substrate be for two crabs (if I get a second one)? Also, please tell me what kind of bulbs to use in the lamp (I have 60 watt Zoo Med day blue bulb and a 60 watt night red bulb).  Trying not to let the crab die, but getting tired of checking the gauges so much. I forgot to tell you, I have a shallow fresh water bowl with a sea sponge and a shallow salt water bowl with a sea sponge, the bowls are the plastic kind specially made for crabs.  One bowl is a ramp bowl that glows in the dark and one is a small circular shape grey plastic bowl. I use the 2 kinds of bottled hermit crab water (one salt, one fresh) from the store. I feed his food in a small clam shell and I give some saltine crumbs, store food, and a small piece of fruit (strawberry, banana, grapes etc). Tried peanut butter but he didn't like it. One day I noticed the grapes got moldy in the dish so I don't use them anymore. Any food to totally avoid? I change the water daily and the food every two days. There is a piece of driftwood, a habba hut and two extra shells. Sorry for the length, I am just worried about the crab.  Thanks! :)Laura

Answer
Sorry I haven't written back sooner, but I have been doing some research for you and I have found out some things for you. Drsfosterandsmith.com sells a hinged glass lid that will completely cover the tank, but has a hinge for easy venting. It is in their fish supplies section. The sunbstrate for any number of crabs should be at least 2 inches, or at least an inch deeper than the crab is tall. If it is a strawberry (is VIVID red with white specks all over it) then it will need a LARGE salt water bowl, because strawberries live right on the beach and sometimes spend LONG periods of time in the ocean, so they need a lot of saltwater to replicate this. To this effect, it would be best if you got a second crab to get another strawberry. Sand will not cause the tank to crack, that's what I use with my UTH and it does just fine. Foods to avoid would be Tetra Crab meal and crab cakes, not only do crabs detest it (they won't touch it AT ALL) it also has many chemicals which overtime kill crabs (ethoxyquin, which is used as a pesticide, and copper sulfate, which is a heavy metal, which hermit crabs are extremely sensitive to). In my opinion, the only prepared canned food to buy would be Crab Island crab meal (not fruit and flower flavored, it has ethoxyquin in it too) It has none of the bad stuff and crabs tend to like it. FMR is also a good brand of hermit crab food. You can look at the labels in your local petstore, if it has any ingredients that are metal sounding (zinc, copper, etc.) or if it basically has a chemical that you can't pronounce, you should probably avoid it. As for fresh foods, My crabs went CRAZY for a special meal i whipped up for them once, I took a single organic egg, scrambled it with baby spinach in organic soybean oil, washed the eggshells and took out the "skin" and crunched the top half up and put the omelette in the bottom half, sprinkled the eggshell crumbs ontop and added an organic tortilla chip on the side, the fought over the chip all night and the egg omellete was almost all gone. Avoid seeds of fruit, most flowers, avocados, chocolate and excessive milk products and you should be fine.