Help with horzontal screen

[k7iou]

SantaMonica I need your help.
I have a 55 gallon with 20 gallon sump.
My horizontal screen size is 10" X 10"
I clean 1/2 screen a week
I use soft white compact fluorescent 40 watt equivalent, 9 energy used in watts.
Timer for light on 18 hours.
I have 2 clowns
1 Blemmy
1 Yellow tang
Sand sifter star
Mex turbo snail
Lots of yellow sponges
1 white sponge growing in sump.
I added the Blemmy and tang about 2 months ago.
A couple days ago I started getting brown algae all over the sand and several live rocks, I used a credit card and cleaned up sand and tooth brush on the rock. It comes off easy and in the sand its is clumpy.
Anyway my algae scrubber doesn't seem to be producing as much green algae as it should and is green, red and brown in color. See picture. Bulb has been changed recently.
I may have been over feeding with frozen mysis and Formula Two, once a day about 1/8 cube each.
Without totally redesigning my algae filter, do you have a recommendation on getting the green algae growth up? I also use a protein skimmer NA6, and have never done any water changes.

[SantaMonica]

The problem is 9 watts on a 100 square inch screen. And I'm assuming you have a reflector so that all the light hits the screen:

12 watts on a two sided vertical screen is for one cube a day.
12 watts on a one sided vertical screen is for 1/2 cube a day.
12 watts on a horizontal screen is for about 1/4 cube a day.

... but you only have 9 watts. And, the screen is way way too big for 9 watts; it can never grow thick because it is too spread out.

So, without redesigning:

1. Up the wattage to 18 real watts.
2. Put a reflector to get all the light on the screen
3. Cut the screen down to 18 square inches.
4. Tilt the unit as much as possible, to get the highest flow.

Horizontal screens are the weakest type, because they are 1-sided, and because the water flows too slow and gets too thick. So you have to make up for it with more wattage.

[k7iou]

I was looking for my post and it was moved. The only way I found it was looking at my attachments, found the picture and clicked on the link.
fyi I had several problems posting, I was logged in typed
it out and hit the advanced tab & was notified I had to log in.

Anyway I have a big round reflector, I chose horizontal because all the vertical screens I tried did not flow evenly, clogged & had spotty growth.
The horzontal screen I have has great flow.
I tried a higher wattage a year ago and itwas burning.
But I will try again.
Using the old specs I was slightly small.
I plan on updating to a larger tank in the future.
Thanks for the help.
I will keep posted if the the higher watts helps.

[kerry]

I have a 10G with a horizontal and feed 1/2 to 1 cube a day. Its much smaller then yours at about 2.75"x6.75", mine is only 18.5625" total. I am use to run a 23W over it now I have 4 LED's. Get you screen smaller as SM suggested you will see results VERY fast.

[k7iou]

Put a 19 watt in the light and will see what happens.
It was working good but I suspect the problem has to do with my RO system. Just checked it and my last filter change was March 2011!
Been also having a CA problem as it went high so I havent had to add any. I suspect the CA is coming in with my RO water!
Changing filters today!

[kerry]

I tried the light thing to, all these months I was just ignoring all the right facts about how big the screen needs to be. I didn't figure it was that big of a deal until Floyd said in a post he cut his back a bit and noticed his fill in greener. So I fallowed suit and I got the same results as well. I have not seen my Calcium play any role in my algae production.