Rust color algae all over LR

[pike]

I have been fighting this brown rust color Algae for the past month every time I clean it come back worse then before.
I have taken my LR out and cleaned it by rinsing it off with the spray hose on my sink. Town Water.
55gal tank, Plenty of flow, mostly up and around the tank, not much pointed right on the LR but it flow everywhere well only one real slow/ dead spot.
I have two power heads and a mag 3 for flow in the tank. HOB filters flowing around 800 gph. Carbon, Purple-Up, Reef Builder,"For Alk", Calcium, coral-Vite, And some food for one toadstool coral and two mushroom, all Rather small.
Two sail fin tangs as big as the palm of your hand. Seven other small 1-2 inch fish.
I have three 40w 48 inch fluorescent, 03Atinic, Triton, and 20k. On for 10 hr a day. "I just switched them to 8hrs a day." with moon light at night.
What is it? What am I doing wrong? How do i get rid of it?

 

[Brenden]

What are water parameters? The sailfins have got to go. Way to much fish for a 55 gal. How old is tank. It sounds like diatoms. Waiting on your response.

 

[seaham358]

Test for phosphates,nitrates and post numbers

what type of water are you using? Is it slimy and easy to blow or suck off the LR? If it is it is cynobacteria. do a search on the site there are tons of posts on cyno, red slime cyno bacteria.
And I 2nd that the tangs need to go soon, they require large tank even when small for swimming room.

 

[demodiki]

No the greatest of ideas to take out the rock and spray it with freshwater. You may have killed off some of the living organisms on the rock. I would also begin testing for ammonia. As said before, your tank is grossly overstocked. What are the other 7 fish?

What source water do you use for top-off water and water changes?