nervous first time crab owner just curious

[weee]

someone gave me two hermit crabs that were just living in sand with 1 dish.
1 is pretty active the other is more slow and hides most of the time.
after researching a bit i see hermit crabs are Not just sand and 1 dish animals.
i want to give them the best care i can.
i have 1 110v heat emitter and 1 60 w day light. no other heat source. the temp seems to be stable around 80. but the humidity drops to 50 and i have to keep spraying everything down. i keep a bamboo mat over most of the top of the tank because it is just mesh in an attempt to keep heat and humidity in. i will be adding moss in hopes of keeping the humidity up more. is it ok to put aluminum foil over the top to keep some of the heat/moisture in? i read crabs are sensitive to metal so i was leery. i am trying to help these crabs but am not really sure if im doing everything ok. i am feeding them commercial food along with a mix of organic blueberries strawberries cabbage kale raisins milled flax sunflower seeds and regular oats. i am not sure if they are eating as i dont see them around the food often i have had them for 4 days. i also have put cooked chicken in but they did not seem to want eat it either. also i bought shells from petsmart in a bundle some were like oyster shells some like hermit shells the bigger of the two sized up a shell for quite awhile but never moved into it. afraid the shells are bad. i just want these hermies tobe happy and really have no idea what im doing. would it be ok to put in a pond like area separated from the sand/eco earth portion? i think that mixed with moss would keep the tank more humid. could i add other things like water crabs frogs or salamanders? i have a reptile pump. i did not see too much information on the net about this. will research some more. sorry post is random and jumbled. ive inserted a pic. do you think it looks to crowded for two small crabs? ive mixed live and artificial plants the live is wheat grass i heard they are prone to eating grass and it was easy to cut up and seems will be easy to replace. http://imgur.com/a/dpM4Q

[aussieJJDude]

You could wrap the top with cling wrap to keep in the humidity and then place over the cling wrap with foil if your a bit unsure?

Best vet would be to turf the the commercial foods, often they contain fillers and preservatives which can make them ill. A balanced diet of fruit, veggies, meats and 'others' (natural foods) would be more ideal for them and give all the important food groups they need. They dont eat much anyway, so dont be alarmed if it looks like they are not eating.

Judging by the pics, some of the shell selection look like great choices. I would recommend when you can, to go out/online and purchase more, to give your crabs as much options as possible.

When you mean pond area, do you mean a deep water dish or a container to separate the sand and the EE? Cause, either way its fine,and in fact we encourage owners to have deep water pools so crabs can 'wash' themselves out, or to replenish shell water.

Moss is a great way to increase humidity! So would recommend adding in some to see if i can help.

No, you shouldnt add any other types of animals with the crab, unless the tank is large enough that you can have appropriate areas for all species and you have kept each species for a number of years so you become accustomed to their needs and welfare. The only animal that i would suggest, is a pillbug or isopod clean up crew, which eats all organics and helps prevent fungus growth.

What i would suggest is getting rid of that bark, it could cause problems if its gets into their shells and go with EE, which is more fibrous, almost like dirt. Getting deeper water pools as well would probably help, and if you position them in front of the heater it will help give you a humidity boost.