Back to the algae, you do not have any problems. This is natural and a benefit, and you will never completely eliminate it in a healthy aquarium.
Those of us with live plants have to keep algae minimal, because it can encrust the plant leaves and smother them, killing the plant. But when live plants are not present, algae is a benefit. It functions much the same as plants, though minimally, by taking up nutrients and producing oxygen.
As I think someone mentioned, if you have nutrients (and with a live fish being fed, you do) and light, you will have algae. Enjoy it.
On the snails, be careful, as the larger snails can add to the bioload more than many realize. The small snails like the Malaysian Livebearing Snail or the common bladder/pond snails would be better. These too are beneficial; their algae-eating is not much, but more importantly they get down everywhere to eat everything, breaking down the organics faster for the bacteria to handle.