I had a problem algae when I was feeding flake & pellet food and up to 3 times per day. The algae loved this dissolvable food making my water very nutrient rich. Now, from recommendations I feed the frozen mysis shrimp with excess liquid strained through a coffee filter, and only two times per day, with a bit of pellets. The problem algae has decreased quite a bit. The critters keep everything else pretty clean.
But you may be already employing that technique hey!! If so, perhaps it will help someone else who reads this.
I also now have a deionized water system... but I just used it with a water change today so I can't comment on its effectiveness quite yet!