Eeehhhh......sorry
@Byron , I have to respectfully disagree. Play sand is usually very dirty, and takes a LONG time ton clean (I once had a friend who tried it, and it took
forever!) Not all pool filter sand is white. And did you say white sand hinders fish? Not entirely true. I personally don’t like to use white sand, only because the waste of the fish, shows so much!
First point--having more dirt in the sand does not make it any less useful as a substrate. Rinse it more if you like, or leave some of it in, it will not harm fish or plants. The play sand is probably the ideal substrate sand because of the positive aspects over many/most other sands: natural in appearance, very smooth so safe for all fish, good rooting medium for substrate-rooted plants, and inexpensive (nothing is less expensive).
There is black pool filter sand, sxo I have been advised, though I have never seen it. White sand is detrimental tro fish. There is plenty of evidence3 for this, and no reliable fish author will say differently. white reflects light from the substrate, something that does not occur in the forest streams where most of our fish live and for which they are "programmed" by evolution/nature. They "expect" it to bee dark beeneath them, which is why the dorsal surface of most fish is dark and the ventral is light. When the fish are swimming, predators below have more trouble seeing them against the lighter surface, while predators above have more difficulty seeing them because of the darker substrate below them.
Just one example...the "adolfoi" species of
Corydoras all share a sand (buff) tone body, with an intense black dorso-lateral stripe, and an orange post-orbital fleck. Viewed from above over the sand of their habitat which is littered with twigs and branches and leaves, the fish if perfectly motionless cannot even be seen. Put a fish like this over a white substrate and it will be stressed, that is certain.
I also find white-substrate aquaria difficult to view myself, as the glare from the overhead lighting is strong. If it bothers me, the poor fish must be suffering even more. Read the profiles on Seriously Fish for forest fish; most if not all will suggest a dark substrate for the better health of the fish.