Phosphates

[jfenton954]

Do algae scrubbers remove phosphates from the water?

[SantaMonica]

Yes.

Phosphate, nitrate, nitrite, ammonia, ammonium, urea, copper, CO2.

[jfenton954]

Why does the light algae still build up on the glass? Also my screen has a red slime algae? I changed the bulbs 2 months ago didn't change when I first changed them at all. I have a 75g tank 4 23w cfls bulbs on a 10x11 inch screen. With a 800 gph pump dedicated for the screen. It use to grow great but slowly went away. I have 165lbs of live rock 120lbs sand feeding 6 cubes of food a day. Lights on screen 18 hours. Water still tests good.

[SantaMonica]

Glass algae is largely from pee (ammonia) from fish; it hits the glass before it ever reaches your scrubber or rocks or sand.

Looks like you need much more light. Increase hours to 22. Move the light closer. Get more wattage.

[jfenton954]

Ok thanks, I'll do that.