Back in late August I built a algae scrubber. To this day all it has grown is diatoms... Info about the scrubber: Waterfall style, screen is about 9" x 4", uses an individual pump to supply flow 295gph pump and most importantly the lights... rapidled solderless leds, 4 reds and 2 blues on each side. (6 leds per side). Controlled by a dimmable driver. Leds were basically copied from kingofdiy supercharged algae scrubber video. Started the scrubber running 18hrs per day at maybe 15-20% power. Only diatoms grew. Did this for 3 weeks. Read some stuff online then switched to 9hrs per day at maybe 25-30% power. Did this for 2 weeks. Still nothing... Kept the lights running 9hrs per day but increased lights to nearly 100%, maybe 90%. Left it like that until 2 weeks ago when I changed it back up to 12 or 14 hours, can't remember... the point is still no growth. Any thoughts on what's going on here? There has been no hint of green growth, only diatoms. Side note about the screen before someone says it... Yea it's rough, very rough, I used sandpaper and then a drill bit used to drill holes (like for bulkheads or doorknobs). Tank info: Setup 4 months ago 120g with emerald 39 trigger sump 8 fish 2 shrimp Feed twice per day about 1 cube or more per day Used tap water until 2 weeks ago when I got an rodi system No algae in the display besides a few diatoms here and there... recently upgraded to a real reef light (photonv2) and getting a little bit more in the tank but nothing crazy. Nitrate between 10-20 phosphates 0 No idea what's going on here. Thinking of taking it down and trying a refugium. Let me know your thoughts!