Hermits/snails in 10g tanks

[CAPSLOCK]

I want to do an experiment for oceanography, to test if temperature affects metabolism. My idea is to do a pair of 10g tanks, with a pair of hermit crabs or snails in each. Feed them the same amounts, measure nitrates. They'll probably just have a normal filters, because I know they're available, with no filter media.

Questions:
How cycled would a 10g need to be to house 2 hermits/snails (with no LR)? Could I just let it run a few days empty, and then keep a close eye on the parameters?

How low a temperature could I keep hermits/snails at... I was thinking one tank at 80, one at 70? Or should it be like 72 and 82?

Is there any way to get a hermit out of its shell (to weigh it)? (This is why I was thinking of using snails instead, just assuming their shells are the same density and what-not.)

Or any other suggestions/advice?

 

[1979camaro]

well, the hermits aren't going to create very much biological load so i would think if you just wanted to run a hermit per tank or something you would be alright without LR. i don't think you can get a hermit out of its shell to weigh it; have you considered peppermint shrimp instead? they are fairly cheap, hardy, easy to feed, etc etc and woudln't need removed from their shells to weigh

 

[CAPSLOCK]

I thought about shrimp, but I haven't had luck with them in my tank (I plan on keeping them afterwards). Then again, I've only tried one once. I thought they were more sensitive to stuff than hermits/snails, though.

What would a shrimp need in a tank to hide in for a few weeks?