Bare bottom tanks for fry fishes is a good way to help keep the water cleaner. The fact that you can see the dirt should be a warning of how much overfeeding you may be doing so it actually helps YOU control your feeding amounts. ( You just use some airline tubing attached to rigid tubing to siphon it out without getting the fry.) It also helps the fry find their food more easily. Once the fish get a little bigger, you can transfer them to a better decorated tank or decorate the existing tank. I use either live or plastic floating plants for the fry when first born so that they are protected from the Mother.
As for a clean up crew, I use small bristlenosed Plecos ( which I am breeding) and just keep 1 or 2 in the tank with the fry. This way, I don't have to worry about any predation from other types of catfish or scavengers.
Hope this helps