Hey guys, I have 10, 20, and 30 gallon aquariums. The 20 and 30 are fully stocked, same with the 10. The 10 has 6 harlequin rasboras, and 1 betta. I know most people are like that's perfectly stocked or some might even say overstocked, but I really want to add a few more fish. Would it be possible to add maybe 3 otocinclus? I know they like schools and need room but would it work with regular maintenance and what not. I have driftwood and real plants in the aquarium but I have gravel. Would that also be a problem? I have sand in the 20, and would they coexsist fine with corycats? I'm just worried it'd be a fight for food because my fat opaline gourami always steals the wafers...