It depends on how big your crabs are. If they are mini or small sized 5 gallons should be enough; but if they are medium, large or jumbo, they'll need at least 10 gallons.
Up to 2 small ones or 1 big one.
then get them! in fact, PLEASE do!! they love company and will become depressed if they don't have any. make sure to have a 10-gallon tank for two crabs though~
I'd say no more than 6 medium sized crabs in a 55 gallon tank.
Hermit crabs and turtles NEVER should go in the same tank! hermit crabs need a ton of humidity, and turtles don't even live near hermit crabs, plus hermies can drown. Hermit crabs need their own tank. 2-3 small hermies need a ten gallon tank. I don't know about turtles, i would also get ANOTHER ten gallon tank.
It depends upon the size of the hermit crab. You can fit 5-7 small crabs in a 10 gallon tank but only 1 or 2 large crabs. The more room you leave for your crabs the happier and healthier they will be. be careful not to overcrowd your tank, cos the hermits can get stressed, and may leave their shell or crawl into a corner and sulk :) But probably two or three would be enough room
When you have a 20 gallon tank for only 2 or you have 30 hermit crabs, bubbling thing in water and dont have any friends execpt hermies
Yes its very good for the hermit crabs body!
You already know what temp, humidity, kinds of water, ( if you don't google how to take care of hermit crabs) You can have alot of space like 3 small hermies in a 10 gallon tank and have diffrent shells, climbing toys (not too many) diffrent foods (hermit crabs are scavengers they can eat people fruit and veggies).
i suppose they could fit, but they need lots of room to move around in. So a ten gallon tank would be the smallest size for two hermit crabs to live in
No hermit crabs need high humidity (70-85%)
Well if you have a friend who lives close and has hermit crabs then when you are hanging out at each others houses you could bring your hermit crab with you and put it in their tank. (You need a little moving tank. The very small ones with a little handle on the top.) But when you leave you need to bring your hermit crab with you. ~EEE2
Well for the safety of your hermit crabs i would use the basic rule of 1gallon of tank space per hermit crab..... so you could get any size you want.... but lets say you had a 10gallon tank so you could have 10 hermit crabs in the same tank.