The sand should never be WET. Condensation doesnt mean anything about humidity, you must invest in a humidity gauge or hygrometer in order to see what the level is and YOU MUST have lights, hermit crabs need 12 hours of light everyday and the need the warmth from that light, A UTH alone doesnt provied that, it only heats the substrate.
Also please make sure both waters stay in their tank, they must have access to that at all times.
Start over with dry sand, add that waters in dishes and then their food, make sure you have a SOLID cover WITH LIGHTS and have the UTH on the bottom of the tank.
If the humidity is too low you can make 1/2 of the substrate moist coco-fiber bedding which is called eco-earth from ZooMed it is a compressed brick that needs to be re-hydrated in de-chlorinated water and then used moist and that is the ONLY substrate that is ever to be used moist.
The temperature should be between 76-82 degrees F at all times and then the humidity must be between 75%-85% relative.
Also please make sure the water you give is NOT tap water but either bottled, distilled or treated with a de-chlorinator without stresscoat in it.
If the humidty is still low after you have used the suggestions above then place a large natural sea sponge in the fresh water dish and that should help. Also, what size dishes are you using? THey should be large enough so the crabs can get down into the water and flush out their shells and bask in there if they want.
If with larger pools and sponges it is STILL low (which it shouldnt be) then add a small air pump with bubbler stone into one of the dishes and then the humidty will be great.
If you need more help please email me directly at hermitcrab_rescue@yahoo.com
Who am I?
We own a Land Hermit Crab Rescue, adopting unwanted, abused, neglected sick and injured land hermits for re-habilitation and placing with our on site colonies or placing into their forever homes elsewhere. We have placed countless numbers already. We currently have 48 on site in our established colonies.
We also offer free educational services for both current and future land hermit crab owners. We also offer the same services to pet stores and other retail outlets, including providing proper care sheets etc.
We offer advocacy services also, helping spread awarness and to intervene when abuse or neglect is present, offering aid to correct the problems or ask for surrender of the animals to us so we may rehabilitate them to perfect health. We also are planning on doing educational and advocacy visits to schools in our area in the fall. Later branching out to other areas.)
We have studied and researched every aspect of the land hermit crab for their natural and captive lives for over 15 years. and we have owned then the entire time in fact our eldest crab is 15 years with us!
Our home on the Web at: http://www.geocities.com/hermitcrab_rescue/
New Forum too: http://crabrescue.proboards102.com/index.cgi
Our Blog at: http://mexicrabs.blogspot.com/
Our Store: http://www.cafepress.com/crabrescue
OUr help site