Saltwater Filtration Question

[DreaminginBlue]

Hello all!
I'm a truly freshwater aquarist, but my efforts to help my sister with upgrading her land hermit crab tank have finally brought me to this side of the forum.
I'm planning on building a saltwater pool for the hermit crabs in their new tank when we upgrade them, as they need one to regulate the salinity in their bodies and help with molting. They currently have one of those tiny reptile dishes with "saltwater" for hermit crabs. This isn't truly the saltwater they need, and that brings me to my first question. What is the best saltwater conditioner, or the one that you prefer?
Secondly- I have a question about filtration. I'm not sure how large the pool will be, but I think at most it'd be two gallons. I know it's almost impossible to cycle such a small body of water, but I'd at least like to have a filter to help with mechanical filtration in keeping the water clean. However, I know nothing about saltwater filters. Google searches have proved futile, though I once stumbled across one hermit crab owner maintaining a five gallon pool with a small protein skimmer?
What would be the best method of filtering the water? What kind of filters or other appliances could I use?
I don't think that I could use a freshwater filter, and that's all I really have knowledge about. Any suggestions or advice would be much appreciated.

Thanks,
DreamingInBlue

 

[DreaminginBlue]

I'm thinking I'll just have to use a freshwater filter, as even more digging through Google has offered no better alternative. I can't think of any other ideas and I don't know who to ask; I doubt LFS has any clue.

 

[cgthebeast]

I think a internal menchincal filter or water fall filter would be best. I know tetra makes a super small one that's easy to change out, plus it has a bit of room to fill with media. Also the airation caused by the water movement will help with the humidity for the tank as land hermits require high humidity to molt.

 

[DreaminginBlue]

Okay, I'll look into those! Thank you so much. She's been having humidity issues in her current tank (it's always too low) so I'm hoping that the water features and moss will help keep it stable.