HCA: Hermit Crab Association

I have a 75 gallon tat that I am wanting to put a couple 2.5 gallon tanks in as pools. The local tropical pets store offers salt water for $1 gallon and says that a bubbler is enough aggitation to suffice for crabs. Can this water be trusted and are bubblers enough. Or should I put in a waterfall wi...

I sawa this crabitat in person yesterday and couldnt stop talking about it last night. It really is better in person. I am already starting to hunt and save items for a tat on this scale.