Maybe I live in the wrong area but my home depot does not carry pool filter sand, just play sand which is too coarse for my liking, sorry for the high jacking.
Bare bottom is easier to clean, gravel looks nice and take more work to clean, Sand looks the nicest ( I think) and is the most work, sort of. But yeah totally up to you. Do you plan on having fish that like to dig? A lot of chiclids like to dig around so it's kinda nice to have something for them to do.
You can't use a gravel vac to clean it because it will just get sucked out. But i just stir everything up when i do a water change. Also you can just carefully run a hose over the top to suck up the light debris without getting sand.
A good trick is to have your drain hose in a bucket outside, water a debris overflow out the bucket and the bits of sand you suck up mostly stays in the bottom of the bucket. Then you wash the sand and toss it back in the tank.
10" jack 7" mida or red devil not for sure 6" Oscar and a 6" green terror there getting to big for my 75G I have just wanted to see what would be best for the bottom?
I found the best way to deal with sand is to keep an extra bag on hand($5) and just go with it. I add more sand over 3 or 4 months to compensate what I vacuum out, lifes to short to worry about loosing 50 cents of sand a month.