Well for the longest time in my 120, I had 3mm t grade black sand and it was awesome but slowly as everyone in there grew (tiger oscar, delhezi bichir, senegal bichir, 2 ornate bichirs) i started seeing one thing: poop. It would all just sit on the top so I was having to do waterchanges like crazy (which of course isnt a bad thing but you know...) So after getting angry at looking at that forever I finally painted my tank and went bare bottom. I figured if im cleaning it all the time I might as well do something to make it easier. But now without the sand it just looks even worse and Im waterchanging every 2 days almost lol. So my questions is what would be the best idea for the tank? I was thinking of doing natural gravel to get some bio filtration going but I just dont know if it would cover up all the crap so I could go back to doing weekly waterchanges rather than a million. Substrate suggestions?