I am starting to feel like I actually reached the balance in my main aquarium. Plants are growing well, algae is minimal and I've even found a better way to keep the hornwort where I want it.
But there's one problem I hadn't forseen. Cherry barbs are pestering the oto. They keep nipping at the spots on its tail base and ends of the fins. I hope once they realize the other fish's spots aren't food items they will leave him alone! Otherwise I guess this tank isn't a good place for him either.