dark grean powder algae

[attachment=2:2qccuti8]1.jpg[/attachment:2qccuti8]i have now using the scrubber for 2 month and all iget is very dark to floursent dark green " like pickles" i have 2500 litre pump with screen 10 inch with copact floursent 23 watt on each side and it is loose not strong algae it looks like paper not hair
[attachment=1:2qccuti8]2.jpg[/attachment:2qccuti8]
[attachment=0:2qccuti8]3.jpg[/attachment:2qccuti8]

the empty spot was a brown spot and i completely cleaned it

i have double plastic canvas" window plastic" i dont have plastic canvas in my region at all ... and i used sand paper to rough it... need to know the problem
best regard

[attachment=0:3vdosk39]4.jpg[/attachment:3vdosk39]

I don't see a problem other than the bald spot. The question, is how are N and P and nuisance algae in the tank?

Bald spots are caused by too much light relative to how much iron the algae is getting. The more light that algae gets, the more iron it needs too. CFL bulbs tend to make bald spots because all the light is concentrated in one spot, while the edges of the screen don't get enough light. Aside from switching to T5HO bulbs, here are your options from best to worst:

1. Get more flow. This will deliver more iron to the algae and let it grow again in the bald spot. Your screen needs to be very rough, however, to hold on to the algae in the higher flow.

2. Add iron, such as Kent's Iron+Manganese, per the instructions.

3. If adding iron did not fix it, and you can't add flow, then move the lights farther back. This will spread the light out more evenly across the screen.

4. If you can't move the lights back, then either use smaller bulbs, or reduce the number of hours that the lights are on.

hi santa thnx for reply

the bald spot was brown algae and i cleaned only completely this spot before i posted the pics with two day

the problem is why my algae is not hairy type it is like paper or pieces that not so strong
nitrate is 10 mg phospaht = unfortunatly i dont have test kit
i also have red slim algae in my tank i stopped feeding flakes and am now feeding natural food like shrimp and clams to minimize phosphate i am using ro water
120 gallon with sump > live rock and it is not heavy stock tank

First, remember that all algae does filtering, including very dark or black growth.

Dark growth is caused by high nutrients and weak scrubbers. Since the scrubber can't grow fast enough to get the nutrients down in a day or two, the growth that does grow is dark. A stronger scrubber would get the nutrients down quickly, and the growth would start turn to green by the end of the week.

But you don't need to change your scrubber; most scrubbers will get to green evenually, as long as they are not too weak. The trick is to clean the screen more often; every 3 days if the growth is a dark oily or black growth. After the growth turns to a lighter brown, switch to cleaning every 5 days. After you get some green, switch to 7 days.

Of course, anything you can do to make the scrubber stronger will help speed up the process.

thnk u santa i will wait and see

hi santa here is my results after 7 days the green algae is not yet hairy type
and still dark green
i also found some dark red green algae in the middle spot ? is it cyano as i have cyano in the main display
i aslo added foil reflectors two days ago before scrubbing
please analyze my results
[attachment=0:r4ml3hcd]alg2.jpg[/attachment:r4ml3hcd]
[attachment=1:r4ml3hcd]alg1.jpg[/attachment:r4ml3hcd]
best regard

Looks good. Now that nitrate and phosphate is coming out of your tank, it will start growing greener next time.

some body told me that i am over feeding
cause i feed them too much srimps twice a day in addition to pellets and flake
my nitrate is very high = 25
should i reduce feeding

The scrubber will take care of it. Give the nitrate 4 weeks to come to zero.