Ah, just remembered something that is sort of on topic. When I was a very little girl my grandfather had a 200+ gallon tank full of tropicals. One fish in particular was a common pleco. He ended up having to trade that big guy in because he got over a foot long in a pretty short period of time. Never once did I see algae in that tank.
Really he traded it? A foot long is not too big for a 200. Common Plecos are in huge demend from Oscar Enthousust. If I remeber right farms dont raise them big enough. So people hand there adult ones to the Oscar enthusoust. They get a baby repeat cycle. I would not reccomend that strategy though.
Oh okay. Was it smaller fish? I want a huge tank for my guppy colony someday. I plan on having that Colony all my life. If there healthy enough Marine/Brackish colony. Water changes are best for algae. What kind of Algae?