Ok little update here, I changed the rock work, use some macro rock I had at home and changed the aqua scaping, it looks okay but I am not 100 happy with it, ill post pictures tomorrow, the kids and I have off today :)
The hermit crab seems fine along with the fish, the poly filter I ordered should be here tomorrow so Wednesday ill be able to get a good idea of what happened. LFS said that it wasn't the tap water that caused it, so maybe I just introduced them a little too soon and the ammonia got em, oops? I haven't heard of ammonia spikes killing off snails but who knows. Either way I wont be upgrading just yet, I might wait till next year to do a bigger tank because it looks like this one will be coming home with me over the summer. I might be moving rooms (crosses fingers) into a more permanent much more chemistry suited room. This will also house a tank MUCH better, I even have a RO/DI unit in the back room if I get the room I think I will.
Anyways the kids raised 25 dollars for a seastar my LFS has a tile star that's small and will eventually outgrow the tank but for now it will be okay and ill throw him in my main display when he outgrows it until I upgrade next year. Im going to add the poly filter see what happens, try out a few snails for a week, and go from there.