yellow growth on front of screen but green on back side ?

[Turtle Power]

hi everyone
im running a single sided scrubber and all flow and sizing is within the guidelines ,what im a little confused about is that I seem to get a lot of yellow growth on the lit side and a dark green on the unlit side ,flow is even on both sides so would I be right in thinking the lit side is receiving too much light ? and that is causing the algae to prefer the darker unlit side ? or is there some other reason ?

[SantaMonica]

Need pics of the yellow.

[Turtle Power]

ok here is a picture ,please ignore the stripes as they are from when I seeded the screen with strips of my previous screen4544
the screen is 6" by 3" and currently lit by 4 x 3w 660nm hyper red leds on 18hrs a day though I used a 14w energy saving bulb to take this picture

[SantaMonica]

Let to go another week.

[Turtle Power]

hi santa here is an updated picture taken the same way as the previous one for a direct comparison ,I cleaned off some of the yellow inbetween this period as it didn't seem to be colouring up so this is about 6 days growth from a pretty clean screen ,I also added a diffuser panel at the beginning of the 6 day period which seems to have cut down on the yellowing quite a bit ,im running the lights 18hr on 6hr off but wondering if I should cut this back ? logic being that the reduced light from the added diffuser panel seems to have improved things so wondering if shortening the light period would also help ?
4573thanks

[Floyd R Turbo]

The screen is filling in well now it appears, you can still let it grow for probably another week to let the holes fill in. You don't want to perform 'hard' cleanings for the first month or so, just remove what you can by rubbing fingertips across the screen and maybe swiping a scraper or credit card across the screen in a dragging motion instead of a scraping motion.

[Turtle Power]

thanks for the reply Floyd ,so do you think I should stick to the 18hr on light cycle ?

[SantaMonica]

Yes keep it the same for a week.

[Turtle Power]

ok will do that then ,thanks santa

[Turtle Power]

hi here are some updated pics ,1st is of the lit side of the screen and second is of unlit side ,should I clean either side ? or just leave it to grow ?
thanks 45914592

[Floyd R Turbo]

At this point I would take a shallow pan of saltwater (from your tank) and swish the screen in it with moderate vigor. This will cause any loosely attached algae to detach. Maybe rub the screen gently with your fingertips to loosen any other growth as well, but not much beyond that (no scraping yet). I see that the top edge of your screen looks pretty bare so you must be cleaning that or blocking the light, that looks good (no flow obstruction)

You might give the screen a very short exposure to tap water as well, but only a few seconds and then dip it back in your saltwater pan before returning to the tank

[Turtle Power]

hi Floyd thanks for the reply and advice , yes I clean the top of the screen every few days with a toothbrush, it seems to be getting going now

[SantaMonica]

Clean.

And get the burned stuff out of the holes too.