Well, everyone who has kept aquarium for some time would have come across the algae at certain point.
Before I started to seriously have fish, I did intensive research. One of the topics I came across most was algae.
Believe it or not, I was actually cheering for algae when I first started due to the unusual circumstances.
I bought 6 Zebra Nerite snails before I got any fish at all. They were said to feed on algae, and they have beautiful shells. The eventual reason to get them was for helping with algae control. However, when I just got them, the tank was new and there was 0 algae. I worried they might starve to death, so I was even asking how to have algae haha.
Later, algae indeed come. I had bought Otoclinus catifsh and Zebra Nerite snails, as well as Red Cherry shrimps and yellow shrimps to keep the algae down. Even my Platy and dwarf gourami would chew on the algae grow on the plants throughout the day.
I have never had green water, but the algae grow on the plants could be a problem, which I have to trim them quite often and throw away the algae covered leaves in order to keep the tank in nice (looking) condition.