Dual screens CFL ATS design

[hobbyist]

I think making the light box out of all mirrored acrylic would be best. Although, the mirroring won't last forever in salt.

The box will be made of black acrylic. Thin mirrored acrylic is then line the inside of the box. Sounds like it would be better to hold the mirrored acrylic in place using something like cable ties instead of glueing. So that they can be replace when necessary.

Your wattage will be limited by melting. Overpowering the screen is easily fixed by reduced hours.

My current ATS has a similar size light box that is just 1" wider. I have been using 3 x 28W CFLs with no melting issue. I guess the open top really helps vent the heat.

Space is the biggest limitation here so the size of the ATS can not be increased. Instead I want to maximise the performance with more light and flow. If melting is not an issue and overpowering the screen can be controlled by reduced hours, would it be worth while to use 3 x 23W CFLs and increase the flow to maybe 600 Gallon (44 Gallon/inch)?

I remember seeing your reply to another thread (don't remember which though) saying that algae actually does more filtering during the dark hours. In which case wouldn't it be better to have more light to maximise the growth and then reduced hours to maximise filtering?

A 2-sided screen is at least 100 percent stronger than a 1-sided one, with the same watts.

Wow!

[SantaMonica]

algae actually does more filtering during the dark hours. In which case wouldn't it be better to have more light to maximise the growth and then reduced hours to maximise filtering?

Not more filtering; it just continues the filtering. But the filtering it does at night is based on how much it grows from the light. So you still want to maximize growth.

[Floyd R Turbo]

How much flow were you using?

780 GPH on a 20" screen, but due to the space, it had to have a double-90 below the tank to go up, then another 90 to go to the scrubber. That is a lot of flow obstruction, so it wasn't perfect.

As for the emergency drain idea, that's a good one. I would put the lower side wall opposite of the drain side.

What is the advantage?

Well, your design sits on top of the trim of the sump, right? If for some reason you have a drain plug up, and the box fills, it is not going to simply spill nicely out of the top of the box. It's going to cascade down the side of your sump and onto the floor. The top edge of the emergency drain slot/hole needs to be below the trim of the sump no matter what.

[hobbyist]

Another revision.

Light will be 3 x 23W on each side to maximise growth. It can be easily changed to 3 x 18W or even 2 x 23W if necessary.

Flow will be 600GPH and the drain will be 1" instead to cope with the increased flow. The flow can be tuned down if needed. Same with the drain, it would be easier to reduce the pipe down to 3/4" if 1" drain turns out to be too fast for 3D growth.

The side of the screen box for emergency overflow is lowered as well as moved further in. Another side panel about 3/4" away is added to make sure water will only flow down to the sump.

Should the slot for the screen be wider than 1/8" for the higher flow?

[attachment=0:33ivrvb4]Emegency Drain.jpg[/attachment:33ivrvb4]

[Floyd R Turbo]

I would say start with 1/8" and if you have to widen it, then you can. If you started too wide, you would have to make it again.

[hobbyist]

Thanks to all the input from SM and Floyd, I have build the ATS to the design and spec shown in the previous posts.

Here are some photos.

[attachment=2:1u8ix4af]Screen and light boxes.jpg[/attachment:1u8ix4af]

[attachment=1:1u8ix4af]Screen box.jpg[/attachment:1u8ix4af]

[attachment=0:1u8ix4af]Light box.jpg[/attachment:1u8ix4af]

[hobbyist]

[attachment=2:37n7ktvs]Pipe and screen.jpg[/attachment:37n7ktvs]

[attachment=1:37n7ktvs]Light and splash guard.jpg[/attachment:37n7ktvs]

[attachment=0:37n7ktvs]Light and splash guard 2.jpg[/attachment:37n7ktvs]

[hobbyist]

[attachment=2:2lu4eve1]Cactus rough.jpg[/attachment:2lu4eve1]

[attachment=1:2lu4eve1]ATS in operation.jpg[/attachment:2lu4eve1]

[attachment=0:2lu4eve1]Screen in operation.jpg[/attachment:2lu4eve1]

So far everything is working as planned. The light box got through a 5 hour melting test with no problem. As in the last photo above, there is about 1.5" water pooled at the bottom and hopefully will help with some 3D growth. Even the emergency overflow works. When testing it by blocking the drain completely the water got to within 1/2 inch from the top of the box, but then drained down the side into the sump with no spill at all.

[itzrulez]

really nice build!
make some photos of everthing in sump!
and dont forget to show some result!

[Floyd R Turbo]

Very nice!

I would still add a cross brace along the top edge of the screen box. It will warp outward right away. You don't need much, about a 1" wide strip of 1/4" acrylic will do, and it wouldn't absolutely have to run the whole length, if you have space between the box and the lamp sockets that will do. You will likely have to take the scrubber offline to do this, because it will have started to warp even after a day of running it, so you'll have to clamp the front and back pieces in place to allow the weld joint for 24 hours to properly cure.

If you don't do it, it won't detract from functionality, but you might eventually get enough warping to cause stress on the vertical joints. That's what happened to mine, and last time I cleaned it I got my hand in there too far and popped the joint open from the top to about 1/2 way down. I ran a bead of weld-on 16 and sealed it up, but it made a mess. But, I need to re-build it anyways after everything I've learned.