I'm trying to find pool filter sand to replace the gravel in my tank. First I can't find it anywhere in town (not many can sell pools in a place where it rains all the time) so I go to look online and lo and behold there are lots of different types all claiming to be the best for your pool because of factors X, Y, and Z. So what I want to know is:

What kinds of sand are you all using?

Where did you get it?

How much do I need for my 10g tank? (I realize I will probably need to buy a big bag)

How deep does my sand floor need to be?