JMO, but you might consider a smaller screen and fewer LEDs. Unless you think you will be feeding 3 cubes/day on a regular basis, it's big. You can make a scrubber 2x larger than the feeding guideline, but IMO once you go larger than that you have diminishing returns and possibly a few negative effects.
Even based on the old square-inch-per-gallon guideline, you're a bit on the big size.
I run a 4x6 screen with 6 DRs on each side on a 120 and another (same scrubber) on a 140, both fed around 1.5-2 cubes/day, those tanks have been running scrubber-only for 1-2 years without water changes for lowering nutrients, and N=0 P<0.06 on both tanks. Actually I don't think I've done a PWC on either of those tanks in over a year. Built right a waterfall scrubber goes a long way.
Well I guess I can take it apart and change it... he built it when he had it set up. I know nothing about them. The only reason he had it was for pod and thats the reason I want it... I want a mandarin dragon
Ah yes, I see that now, I skimmed the thread a bit too fast. The CFLs will work fine if you want to keep them for a while until you build the LED array. I would replace the lamp though and for that size screen/tank I would use a couple in the 23W to 36W range with large (10") reflectors.
If your goal is to support a mandarin dragonet, don't count on the screen to provide these in enough quantity until the tank has matured - IMO, 6 months or so under moderate bioload and algae growing well on the screen.
Like I said, you can under-light the screen and still get the filtration level you want. So there is not an absolute need to take it all apart just to reduce the screen size, just realize that the screen is oversized and this may cause the growth to spread out and not get thick. You will probably still get adequate and effective filtration, but you might see some weird patches of growth like yellow spongey stuff, and dark growth at the edges, but you will definitely have an area of green growth also. Oversized isn't the worst thing, it's just on the inefficient side, meaning it has a longer slot, more water flow required, takes up more space, etc...I would just go with what you have and see how ti goes.
Also have you asked the seller how much growth the screen got, how much he fed, how often he cleaned, etc?
Looks like a custom reflector, and it's concentration the light in the middle, so that's why you see green there and darker around it. Which is fine, if it's doing the job it was intended to do.
Looks like there are some acrylic panels in there too, presumably to keep any sideways spray from getting out of the sump. This is important, so make sure you have something similar employed in your setup.
Yeah I actually built the lights it currently has on it. Its a friend on mines tank. I built the sump and lights how he wanted... he done the scrubber himself