The idea is to build a scrubber with a harvest area of 1 sq inch per gallon of water and you put powerful light on both sides.
Ones a week you harvest only 1 side (half of the screen), and leave the other side to work. When you harvest the screen you just remove the algae with your hand (hair algae) but you don't wash the screen, you left some algae left so it can regrow. After a week you trim the other side, and so on with the cycle.
My scrubber has been running for 5 days, I went for a only 1 side light approach so I use a screen of twice the side and a bigger light, so in my case I will harvest only half of the screen when the time comes.
My tank if a 90 gallon, the scrubber is around 208 sq inches (13' X 18') and I am using a 32 Watt T5 2700 light, for what I have read this is a small lamp, they recommend 23W power compact per side, but my space is limited.
My nitrates has been 5 - 10 ppm for the last couple of weeks, yesterday they were 0. Since the scrubber has been running for only 5 days I wasn't expecting results this soon, so I will let it run for more days before making any assumptions.
Pictures:
This pic is from Feb 7, you can see there is some cyano on the sand and the flat rock in the middle is cover in hair algae.
This is a pic form yesterday Feb 13, the flat rock in the middle has less algae, and the sand looks more clean.
I know my bicolor blenny eats the hair algae form the rock, but before I never notice any advance, I guess the algae regrow on the scrubber this time.
On a side note, I add some livestock this week (2 perculas, 1 anemone, 1 frogspam and 1 mandarin dragonet)
I will post some pics of the scrubber latter, and I will use a better camera, this is the one of my cellphone.