[Floyd R Turbo]

I have not idea how Santa Monica is coming to that conclusion.

Your screen is only 5 weeks old, the growth you have in that time period seems pretty decent. I would just rub & rinse and leave whatever growth stays attached alone, except for the top edge where the screen goes into the slot pipe - there, you want to scrub it to keep it clear of any growth.

Don't over-clean, especially when you are in the maturing phase. That light appears strong enough to penetrate through the growth at the thickness you have in the picture, so there's really no reason to remove that. You only really need to scrape when the growth starts to get thick enough to block, and based on those pics, you're not very close to that.