Building a new acrylic scrubber

[DesignsOnline]

I have started to build a new acrylic scrubber for my tank (5ft long 2.5 ft high 2 ft front to back Bowfront)
it is 2 ft long by 15 inches high & 8 inches deep, it is comprised of 3 sections:

a water tight central section made of clear acrylic drilled at the top for 40mm pipe that houses the screens.
This section is 3 inches front to back with a 40mm pipe running the length of this section, slit at the bottom
and housing the screen. The top of the pipe is removable to allow access to the screens.

The screens are 2 x 12 inches wide by 12 inches long

2 end sections with the lighting in. The outside long edges are made of polished mirrored acrylic, with the
mirror facing in to act as powerful reflectors. 3 energy saver bulbs evenly spaced are contained in each side.
Producing and equivilent of 600 watts of light, but actually ony using 120 watts.

The lid is a pushfit design lipped around the center section to keep it watertight , it is removable and allows
access to the screens, pipe, and the lighting in the outer sections.

The ends are drilled top and bottom, with the 40mm pipe entering one side and exiting the other at the top, with
an end cap to allow quick access to the pipe for blockage, and also to allow me to fit an overflow system in case of blockage.

The scrubber is drilled and fitted with a 40mm 90 degree elbow joint comming off the bottom of the scrubber to allow
me to pipe the water either down in to the sump or elsewhere.

The water enters the scrubber via the pipe connected to the weir in the main tank, and is gravity fed saving on power usage.

ANy comments on this design by santamonica before I complete the build would be appreciated.

[DesignsOnline]

Just to add to the details above, the Accrylic I have bought to build this with is 4mm thick clear, except for the 4mm thick mirror.
I was concerned with evaparation, and suspect that with many of the open "in an bucket" style designs a lot of water is lost to evaporation.
Can anyone confirm/deny this?
I also wanted to keep the sound levels as low as possible (as I already have a very noisy tank)

It was these factors that led to me deciding to build a fully contained and boxed in scrubber.
I have all the materials ready and will be starting to build this on Tuesday morning, therefore any tips or pointers on the design or anything else before I start would be very helpful...

[Floyd R Turbo]

I'm a little lost on a couple parts of the design. Are you cutting the slot tube lengthwise so that you can lift the top off and pull the screen up through the slot itself? That will not work if that's what you're thinking. The growth on the screen will make this impossible to do, plus you need to be able to remove the slot tube and clean it (the slot section)

It sounds like you're using 6 20W CFLs, which is about right. Don't worry about equivalent wattage, means nothing w/r to scrubbers - actual wattage is what matters.

The 4mm acrylic will probably do, as long as you brace it properly. Otherwise the heat on one side and water cooling the other side will cause it to box outward toward the heat like crazy. Plus I would go with 1/4" minimum for the watertight box, it's a lot easier to work with and make a watertight bond.

You asked about the link to the SM100, here is the link

viewtopic.php?f=2&t=502

plans are shown about 2/3 of the way down.

The mirrored acrylic may or may not work, you lose a lot of light power when you have to go through the material twice (once on the way to the mirror, once on the way back) but it's way better than nothing. Polished aluminum is the best but DIYing it not so easy, but you can mod a stock reflector or make a beer can reflector.

Just a few comments for now. Better not to rush into it, take your time and look at as many designs as you can before actually building.

[SantaMonica]

Need to see a 3d pic. Can't tell from the wording.

[DesignsOnline]

Need to see a 3d pic. Can't tell from the wording.

I dont have anthing to build a 3d pic with.....
2d is the best I can do.....

[DesignsOnline]

I'm a little lost on a couple parts of the design. Are you cutting the slot tube lengthwise so that you can lift the top off and pull the screen up through the slot itself? That will not work if that's what you're thinking. The growth on the screen will make this impossible to do, plus you need to be able to remove the slot tube and clean it (the slot section)

Your right that is what I was thinking of doing. I did think the growth on the screen may make it difficult to remove the screen from the pipe, so I was going to simply make the slot in the pipe a little larger to allow the screen to be removed. I am now going to totally rethink this part of the design.

I will have to make the pipe removable from the top, like the sm100 design you showed me.
This gives me a new problem though, I was going to use the pipe running through holes in the sides of the scrubber unit to hold up the scrubber in place above my sump.
However having the groves in the sides to allow the pipe to be removed means that I will have to find another way of supporting the unit above the sump, and unless I cut just enough space to run the pipe right at the top below the lid then it will also allow for evaporation (I want the center section to be water tight and as quiet as possible.)

It sounds like you're using 6 20W CFLs, which is about right. Don't worry about equivalent wattage, means nothing w/r to scrubbers - actual wattage is what matters.

Will that be enough light? it will be three energy saving bulbs on each side of the screen, spaced out at 6 inches along, 12 inches (in the middle), and 18 inches along, plus the mirror behind the lights facing in to the unit. I know that the further it travels the less powerful the light will be, but the only light that will be reflected back in will be light that would have been wasted otherwise, so it should help to improve the spread of light across the screen.

The 4mm acrylic will probably do, as long as you brace it properly. Otherwise the heat on one side and water cooling the other side will cause it to box outward toward the heat like crazy. Plus I would go with 1/4" minimum for the watertight box, it's a lot easier to work with and make a watertight bond.

You asked about the link to the SM100, here is the link

viewtopic.php?f=2&t=502

plans are shown about 2/3 of the way down.

Thanks for the link, I like the way that the light sections are removable in that design, but it looks too complicated for me to replicate, plus im using very different kind of lights.

I hadnt considered the possibility of the box warping, thats a worry as I dont have any thicker material to work with. and the stuff I have got took ages to find...
When you say about bracing what do you mean? (im not a practical person when it comes to building or making things, im a webite designer and a search engine optimisation person)
How would I brace it and what with?

The mirrored acrylic may or may not work, you lose a lot of light power when you have to go through the material twice (once on the way to the mirror, once on the way back) but it's way better than nothing. Polished aluminum is the best but DIYing it not so easy, but you can mod a stock reflector or make a beer can reflector.

Just a few comments for now. Better not to rush into it, take your time and look at as many designs as you can before actually building.

I really appreciate your helpful comments, thank you. Please feel free to make as many more as you think are needed as I dont want to keep making mistakes that could be avoided.
In the meantime, my tank is desperate for the scrubber to get started, my skimmer pupms packed in about a year and a half ago and since then the only filtration has been the liverock and water changes.

[DesignsOnline]

I have had an idea that may help with the problem of heat from the lights a little:

I was going to box in the sections for the lights totaly and drill a few holes in the top of the light sections to let the heat out,
but instead I could add sliding runners in the lid and the base plate and just slide the mirror accrylic in to place front and back but with no sides.
So the sides for the light compartments would be left open to allow the heat to disipate, I could ebven add mini fans to blow along the length of the lighting compartments if needed.

However this would create a new problem, every time I open the lid the whole thing would need to be put back together after, because the mirrored walls front and back would need the lid to hold them in place,
unless I added a partial side to hold the mirror in place when the lid is removed....?

[DesignsOnline]

Modified design to allow cooling, & pipe removal for screen cleaning, any better?
In this version the lid can still be lifted straight off and the central compartment that houses the screen is as watertight as possible still.

[attachment=1:1y4ktk83]scrubber-side.jpg[/attachment:1y4ktk83]

Here is an awful scetch of the side view, (about as close to 3d as im gong to manage lol...

[attachment=0:1y4ktk83]scrubber-length.jpg[/attachment:1y4ktk83]

What do you think of this version, it should allow for cooling to prevent the heat from the lights warping the acrylic dont you think?

[DesignsOnline]

update to original image at the top:

[attachment=0:31bowiu2]scrubber-design-updated.jpg[/attachment:31bowiu2]

[SantaMonica]

1. It'll work, but the spots in front of each bulb will tend to burn since they are so close to the bulbs. Reduced hours will fix this.

2. Warping will occur anywhere that is not supported. If you can push with your finger and bend the material, if will probably warp there.

3. Seems like a complex attempt for a first scrubber, especially since you don't have anything right now. How about just starting with a simple external one first.