I started with gravel in my 10 gal
, and opted for black Petco "aquarium sand" for my 75 gallon. I rinsed and all the stuff you're supposed to, but basically it comes down to letting it sit in the tank a few days, stirring it once in a while with something (I used a piece of PVC
pipe) to get the bubbles out and break the surface tension, and after about a week, starting up the filter. The filter gave me a few false starts, because I got sand in the impeller - took it apart, cleared it, and it worked fine. Since then, the sand hasn't given me any filter issues. As the sand sits for a few weeks, it gets heavier, and is less likely to get sucked up by the vacuum or stirred up in the water. Not sure what happens, but it seems to settle in.
My tiger loach seems to like it, and it's fairly easy to vacuum. Poop stays on top instead of sinking into the cracks and being a problem every time you stir the substrate. Only one ammonia spike while cycling so far.
Planting fake plants is a little tough because they're buoyant, and the sand isn't very heavy, but I found it's really easy to just hold it by the stem at the base with the aquarium-grabber, push down into the sand, and it's sucked up. No digging required, really. But, stuff can get jostled/ dug up easily too. I need to push down a grass mat, come to think of it...
I'm a newbie, so take my experience/advice for what it's worth.