if you want a sand substrate, you can pretty much make the decision based on what you think looks best... i prefer the natural look so i went with play sand, it cost me 5 bucks to fill my 75 gallon with it and i still have a bunch extra. i tried the pool filter sand, that cost me 7 bucks to fill the 75, but it just turned out too white for my taste.
here's a link to my thread in the media lounge...
http://www.monsterfishkeepers.com/forums/showthread.php?t=277393
the first set of pics are with the pool filter sand and then on a later page, there are pics of what it looks like now with the play sand in there.
i also like the look of black sand, but that stuff is just so expensive, i only use that on smaller tanks.
here's a link to my thread in the media lounge...
http://www.monsterfishkeepers.com/forums/showthread.php?t=277393
the first set of pics are with the pool filter sand and then on a later page, there are pics of what it looks like now with the play sand in there.
i also like the look of black sand, but that stuff is just so expensive, i only use that on smaller tanks.