I have had mine online since November 17th. I've had it set at "11 o'clock" for light intensity and lights on from midnight until noon. I cleaned the screen for the first time this last weekend. I didn't remove the screen at all from the time of firing it up until I did the first cleaning. I kept looking into the growth chamber from the end a few times a week checking on progress. I started to see growth at roughly the 4th week. The day I cleaned I also increased intensity to "6 o'clock" and time on from midnight until 6:00pm. Before the ATS, I had a GHA and Bubble Algae problem starting to get out of hand. Before hooking up the ATS my No3 and Po4 was near untraceable, due to the algae. After cleaning the screen this last weekend I tested levels and they were still very low(I'm not remembering what they were at this point, I have them written down but I am in bed right now

). So far the GHA and Bubble Algae has reduced significantly. I'm hoping that the need to clean will be every 7-10 days. The ATS is sitting on top of the sump and is fed with a Eheim Compact+5000 pump that also feeds 2 Two Little Fishies 550 reactors (one with GFO, one with biopellets), both of which I'm hoping to be able to remove at some point.