fish live in environments that have substrate.. 3m colorquartz all the way!
Fish don't live in glass boxes as well. Wanna replicate that too?
What really sucks about b.b. is you can see the cabinet through the bottom glass. I like my black gravel about an inch in depth. All up to you though.
Paint the bottom glass or tape a cover over it.
@OP: Do what you may, BB will always improve the water quality. With gravel, there will ALWAYS be gunk trapped underneath. I don't care what anyone says. I've used gravel before. Switched to about 3 kinds. Every time I would gravel vac, I would never be able to get it all. Even if I did a 100% gravel vac, and I would always gravel vac for my water changes. Sand, meh, sand is alright.. but I have large fish, they dig into it and make hills and eventually some of it got into my filters. Switched to BB after sand.. Was a very big improvement. I would just gravel vac any waste or uneaten food and my water would be, and still is, Crystal clear. Makes it easier to do water changes every other day as well..
