Byron,It annoys most fish, because it is completely unnatural. Light reflects off white which makes it even worse. Fish maintained over white sand are usually paler than those over a darker substrate. The overhead light has an impact too, obviously.
I personally find white glaring to look at in an aquarium. That in itself is suggestive.
Then that explains why half of my panda corydoras are turning pale. I started my aquarium last October and slowly over time their black is turned pale. A few of them have translucent dorsal fins. Without any signs of fraying or fin rot. Tomorrow I'll go to Lowes and buy the grey Quikrete play sand you suggest.
Can you tell me how you would go about changing substrate in a cycled aquarium with fish? Do I remove my fish, snail, & plants into a bucket then remove old/add new substrate? Or can this be done with fish & snail left in the aquarium? (and I work around them). I do not have a big aquarium so it should be somewhat easy either way, but I don't know which would stress them out more.
Glad you mentioned this. No one has ever mentioned to me at a store or friends with aquariums to choose darker sand substrate. White or sand colors are easier to find at Petsmart than the latter.