Some aquarists overstock their tank to "avoid" aggression, which puts a lot of stress on the whole system. Many fish need more food, and more food means more waste products
In general you should feed your fish no more than they will consume in 5 minutes
If you underestimate the importance of diluting the waste products, the algae will have an unlimited supply of nitrates and phosphates to feed on. Do regular water changes or one third of the water.
An algae-free tank with clean windows will remain a utopian dream, but the growth of these lower plants can be kept under control "if" we feed sparingly, keep the fish density low, and do regular & massive water changes.
Using less light could also reduce algae growth, but that is out of the question, as this would lead to an accumulation of even more waste products, what will stress the fish even more.
A good light source will propagate the growth of green algae that are eagerly eaten by most Mbuna species.
Chemicals to eradicate algae should be a last resort and you should concentrate on the real cause.