Anyone tried this with plecos? I have one tank set up with moon sand and guppies, and I'm still contemplating if this is ok with plecos. I have them in shrimp tanks. I asked this a long time ago... haha! Still can't figure it out. Help?
There won't be a problem. However some species will not look their best on a black substrate and can lead to a darker colouration- less contrast in patterns etc. Have used it with the black and white species and it looks nice IMO.
Many species of fish are more comfortable with a darker substrate than with a light-colored one, simple because they don't show up as easily to potential predators. I have some new little catfish split between two tanks, one with sand and one with black gravel substrate. The catfish in the black gravel tank seem less reluctant to lounge around in the open than the ones in the other tank.