Finding the perfect combination of aquarium inhabitants is an art. You want to find species that are compatible with each other in terms of size and color, but you also have to think about aggression and diet as well. Once you’ve established the ideal balance, it can be challenging to add a new inhabitant to the tank. If you’re struggling to control problem algae, however, adding a new species could be your best option. Bristlenose Plecostomus, oto cats, and other algae eaters are a natural and long-term solution for problem algae, but they require care of their own.