Just completed new 7 cube LED Scrubber. What do you think? Also, question on pipe slot flow??

[88flaminchevy]

Hey Guys,

I just completed my first LED scrubber. I've built a few CFL scrubbers, but never an LED. This one obviously looks a lot like Floyd's old design L2, but bigger. I went with a 10" wide by 9" long screen and 72 LED watts (8 3w Red and 4 3w blue per side). As you will see in the pictures, I left the bottom open to drain over my 20G sump. In my opinion, it's the best way to maximize water flow without worrying about a drain getting clogged or limiting flow. I have a sponge between the last 2 baffles of my sump before the return pump, so I don't really have to worry about micro bubbles making their way back to the display tank. My only issue I am having with this one at the moment is the flow coming through the pipe slot. Because my screen is 10" wide, I went with a Tam Rio 1100 which puts out about 400GPH at 2 ft head. I measured the flow with the bypass valve leading to the scrubber closed, and sure enough I am getting roughly 415GPH out of the screen. I throttled it back just a bit and dialed in the 360GPH which should be the right flow for a 10" wide screen. Unfortunately, all the water wants to V down the center of the screen...... The first and last 2" of screen are running pretty much dry. I cut the pipe slot on my table saw as I've always done and cleaned up the cut with a file and sand paper. I'd say the slot is just a hair under 3/16". This is the first time I've ran into this. Any suggestions or comments would be great!!

Thanks!!

[SantaMonica]

Solid build.

Usually if too much flow is coming out of one part of the slot, the slot is too wide.

[88flaminchevy]

Thanks for the complement! I put a good 2 days into building this one nice. From your experience, does dropping the screen pipe from 3/4 to 1/2 help at all? I was thinking that maybe I'm not getting enough fill in the pipe as you mentioned with the large slot. I was thinking if I went 1/2" it might fill better and cause the water to spread out. I always tend to go a bit bigger on the slot to prevent it from clogging once the algae starts to grow. Also, what would you recommend I set the light cycle too? I'm at .8 watt per square inch.

[Garf]

Have you got the screen inserted fully into the pipe, or just into the slot.

[88flaminchevy]

Ya, screen is all the way into the pipe touching the top of the inside. That's the way I've always done it, is that not correct?

[Garf]

That's how I do it also. Suppose you could fiddle with it though, you never know ! I also did this inside the pipe which seemed to even out flow a bit by causing a bit of turbulence inside the pipe; don't mention the turd, I know!
http://i1269.photobucket.com/albums/jj597/Garf1971/243749a9866fe073e0c686217ce3697f.jpg

[88flaminchevy]

Worth a shot I guess. You don't think changing the pipe size will make a difference?

[MorganAtlanta]

It looks like you might end up with areas that are lit with predominately blue and others that are lit with predominately red. You might want to add another 6 reds or so in the gaps between your current layout. Predominately red lighting won't be a problem, but predominately blue might be. The diffuser panel might help that some though.

[Garf]

Worth a shot I guess. You don't think changing the pipe size will make a difference?
I've only used the 20mm pipe so any guidance would be uneducated, sorry. I would be tempted to put a breather hole in the top of the pipe, with an airline inserted, going into the sump (just to see if your getting an airlock) if your gonna scrap this pipe.

[88flaminchevy]

Thanks for the suggestion, I'll give it a try. What about light cycle? Any suggestions?

[SantaMonica]

.5 LED watts per sq in is good. Start with 8 hours since you have more.