Has anyone mixed sand with fine gravel. I assume the sand would eventually sift down to the bottom. I plan to put tapajo geos in the tank and wanted some sand for them to sift through. I did have a red hump years ago and he picked up the gravel just fine. I am putting a rock BG in the tank and I think the gravel should have some of the same colors of the surrounding rocks amd BG - that is why I'm not going with straight sand. Thanks guys