Frosted Tint on Lights
I recently replaced my tank lights after my originals finally gave out. The new lights are LEDs, didn't come with a dimmer and I immediately starting getting algae growth.
I bought some frosted window tint and put it on the lights and so far it's working great. I couldn't find the percentage of light blocked on the packaging, but at first I didn't think it was making much of a difference at all, tank was still lit nicely.
I watched a YouTube video yesterday and the guy (who had some unbelievable tanks!) suggested putting black tape every few inches or so to cut down. He also has many of his lights suspended was above his tanks, but this wouldn't work for me.
I thought I would share this in case anyone else has had this problem, but then, if you have you've probably already figured this out!