So what is your substrate? I am working on switching my tanks over from gravel to sand. I'm doing this for a more naturally looking tank with some low-light hopefully hardy plants lol. Also I'm doing it for the Cories I'm going to stock the aquarium with.
I was going to leave one gravel, but I plan only stocking bottom feeders with my Bettas so I want the best substrate for them. Not only that sand is a lot of fun to play with lol. I mean a lot of fun lol.
For my bettas I use gravel because it's easiest to clean and they have no special substrate requirements. For the goldfish I use large river rocks because gravel can get lodged in their mouths or digestive tract. I don't wanna take that risk. I could even go bare bottom if I wanted to. For my community tank I have sand because I have burrowing loaches. So I guess it really depends on the individual fishes' needs.
I like the look of sand, it's what I have in my 10 and 33. But with my two individual 2.5's I just go bare bottomed. I used to use glass beads, but found out they had paint or something that flaked, those got chucked fast.