2 SM 100's on a 180 reef

A bit of history first:

Ran a horizontal scrubber with so so results for the last year. Then, about 6 weeks ago, moved the tank to new home, and set up 2 SM 100's after the move was complete. As of right now, I'm getting a lot of yellow and dark growth on the screens. I'm on my 4th cleaning. I had very little algae growth in the main aquarium when I moved it. As of today, I'm getting a lot of algae growth throughout the tank, as well as some red algae in a few places.

Phosphates 3 days ago....07
Phosphates today....03
Nitrates...not detectable
calcium...450
PH...8.15

I've never been able to figure out how to phost pic's, so here is a link to my screen just before cleaning a few minutes ago:

http://s997.photobucket.com/albums/af91/jm2drvr/

Any help or thoughts would be appreciated. I am in the process of getting all the pieces together for a 450 gal reef tank. I have everything now except the tank, and the hole in the wall where it will be installed. However, I first want to get my 180 up and running successfully with these scrubbers before I start the next project. I plan on using 3 scrubbers for the new tank.

Thanks again for any help, or suggestions.

If you have been cleaning every week, then it looks like the lights are not being left on for 18 hours.

I confirmed timer set for 18hrs

How much are you feeding?

It looks like nitrates or iron might be limiting. You should have some iron anyways, like Kent's Iron+Manganese, for later when the scrubber is growing bunches. The screen does not have that bright yellow look that usually means lack of iron, but it can't hurt.

For nitrates, you need to find out if they really are "zero", by using another kit, and lfs test. It would be very rare, but if it's the case you can try adding some calcium nitrate from AquariumFertilizer.com, or I can mail you a dose instead. If nitrates were limiting, and you added nitrate, the display algae would increase too for a short bit while the scrubber caught up.

The other way to "add" nitrate is to feed more, which is why I ask how much you are feeding. Feeding adds both nitrate and phosphate, but since you already have plenty of phophate, it does not matter; the nitrate will be brought up from "zero".

So for now get the nitrate tests and a bottle of iron, and count your feedings.

One thing that I failed to mention is that I have done a few water changes over the last week(90 gal total). As my oldest corals have started to bleach out, I got scared, and the only common sense thing to do when you are dealing with coral loss is water changes to get rid of whatever is killing them. Also, I really havent been feeding all that much. Maybe a few cubes every other day, as well as a bit of reef nutrition phyto feast and oyster feast on the opposite days. All in all, probably average out to 3-4 cubes a day. I have been afraid to feed an more as the red and green algae in the main tank is really starting to bloom. I have already been adding iron for the last couple of weeks. With that being said, is your advice to still get a new nitrate test kit, and feed a bit more?

Well the corals can only eat tiny particles, so the cubes would have to be rotifers to do any good. Hold steady for a week, and let's see pics of the screen before and after cleaning. Make sure all the bulbs are working, and make sure the ON time is not accidentally the OFF time. The screens look exactly like they would look if they were only running 6 hours, or on one bulb.

Thanks for the advice! The second scrubbers 7th cleaning is due on Saturday, so I will shoot some more pics then.

Here are a couple of shots of the screen before cleaning on Sat.

http://s997.photobucket.com/upload/albums/jm2drvr/

Test results as of this today...

Phos - .11(previously tested at .03 two days ago)
Nitrates - not detectable
Cal - 450
PH - 8.0

A couple more big chunks of my pink Monty's have bleached out as well. The Monty's use to grow so fast that I would break pieces off and throw them away. There is absolutely no polyp extension for over two weeks on any of the sps corals in the tank. The glass and rocks are really being taken over with GHA. The red algae has almost gone away completely. I have been feeding about 4-6 cubes every other day, as well as phyto feast in between. I have 30 gal of RO mixed and ready to go if anyone thinks or reccomends that I do another water change. I'm sure the question will arrise about flow over the two scurbbers. I am pretty confident that there is at least 700gph for both scrubbers as there is good coverage on the screens, and a good 1.5" of water on the bottom of the scrubbers as well.

Pics did not show.