Split from here: safe-to-clean-behind-light-t16112.html Butterfly
I've also been having recurring "blooms" or "streaks" of algae. I performed this same cleaning procedure today... It looked like a lot of sand or dirt behind the light just sitting in the bottom of the niche. It didn't feel like sand or dirt though, it was really soft. I sucked it out to waste and will cross my fingers. I wish I had an underwater camera...
I've also been having recurring "blooms" or "streaks" of algae. I performed this same cleaning procedure today... It looked like a lot of sand or dirt behind the light just sitting in the bottom of the niche. It didn't feel like sand or dirt though, it was really soft. I sucked it out to waste and will cross my fingers. I wish I had an underwater camera...