Hermit Crab only tank

[skabooya]

I want to keep this fairly small and simple as I need to bring water from home as it is. Our school water is not fish friendly. I learned that in 2011. So cleaning needs to be minimal as I can only dump water in the school drain and carry premixed water from home. As cool as fish would be they would add too much to a bioload.
Shrimp would be neat but I have never had success with them other than in my freshwater systems.
It would be great if I could find a sealed system so evaporation would be very minimal. And really the light only needs to be strong enough to see into the tank. I have heard of people keeping hermits in bowls like a betta bowl but I don't think that is fair, nor would the hermits live for very long.

My gosh I sound like a newb. Ive been in the hobby a long time and I just want opinions LOL.