I've been following the 7 day cleaning rule (+/- a day or two) and was just wondering what the recommended method for cleaning is? I've been scraping away my algae with a credit card sized piece of 1/8" plexi while rinsing w/ fresh water in the sink. It removes most of the algae from the screen but leaves the algae that's inside the holes to regrow, which it does, but I don't see anywhere near the growth I see in some pictures here. I've tried just rubbing the screen with just fingers under running water but not that much algae comes off. I do get that algae growth levels are completely subjective to light and flow. Could I be cleaning too aggressively with the scraping though? How should one physically get the excess algae off the screen?