Looking for opinions on nano design.

[craig1]

Hi all, I've been lurking and learning awhile, and I'm finally ready to start building a scrubber, and would like opinions / thoughts/ comments to validate my design before I build it.

First off, this is for a 28g NANO, and will be mounted above the tank to drop pods back in via gravity.

The design I have in mind is based on the SM 100 acrylic scrubber, but is single sided. Box would be somewhere in the neighborhood of 20" long, I'm looking to use an 18" long, 1/2" dia pipe, So now for the specifics (And questions peppered inside…):

Screen size:
Based on the 1sq/in double-sided per gallon rule, I need better than 56 sq/in for a single-sided, which leaves me with a 14" x 4" minimum screen.
I know SM, you mention that wider is better, but I start to worry about the heat generated from pumping more than 490 gph through the tank, and expanding it to 15, 16, or 17" wide. So is it worth just bumping it to 14"x5" for the extra 14 sq/in of filtering and call it a day?

Pumps:
At 14", this requires 490 GPH. Is this true regardless of whether you're using 1/2" or 3/4" pipe? Seems like the pressure in the 1/2" pipe might be higher, not requiring the same amount of flow from the pump side, but I'm speculating here.
I currently have two extra nano pumps that run 277gph each, so in theory, I could run a pump to each side of the flow tube to get 554GPH, but I'm not sure if this is recommended… Maybe with a check valve on each side so that if one pump dies, it's not just pumping straight through to the other side… Thoughts?

Lights:
Planning on using these:
http://www.pegasusassociates.com/MicrofluorescentT4.html
12w, 17.5in long 3000k, 800 lumens, T4 micros. Their with is only 3/4in, so I was planning on stacking 3 right next to one another to shine on the screen, giving a total of 36 watts.

And that's pretty much it. So my question is does this hold water? Any thoughts, comments, or adjustments?
Also would like to know how far the screen should be from the clear acrylic shield (like in your design) as well as how close the lights should be to the other side of the shield.

Thanks! Looking forward to your opinions!

Craig

And if I do end up building it, I'm more than happy to share the plans with anyone who wants them.

[SantaMonica]

Those bulbs are not 800 lumens... probably 80 max, but more like 60. Nevertheless, for a 28 gal nano, 28 total watts is good, so 36 is better, about 1" from the screen. The length of the bulbs you can find will determine the size of the screen.

Pipe size does not matter. There will be no pressure inside because the slot will release it all. Do no use two pumps; get a bigger one.

[craig1]

Thanks tom. Has anyone found T5s that are smaller than 18"? Wondering if that would be a better choice if I could find them...

[rygh]

A problem with those T4 fixtures is that there is no reflector behind them, or even room for one.
The T5s recommended even have individual reflectors.
That can make an almost 2X difference.

An alternative if compact fluorescents. The bent tubes. Come in pretty much any length and size.
And you can make your own reflector.

Disagree on pipe size mattering.
At 500GPH, that is a LOT for a 1/2" pipe. As such, it will have pressure. Not a lot, but likely enough to
make the amount of water coming out uneven unless you have progressively larger slots to compensate for pressure difference.
Another thing is that when you start cutting slots and such, a small pipe gets a bit wobbly.

[craig1]

Ok, lets try this design...

Double sided screen, similar design to the 100.
9"x4" screen

These bulbs: http://www.planetbulbstore.com/dt18-rs.html, 2 on each side, for a total of 36w per side, 36 sqin of screen realestate.

If that seems like it would work, would it help to use mirrored acrylic as a reflector on the back walls? (opposite the clear screen acrylic).

[SantaMonica]

You only need one of those bulbs per side, unless you are breeding or liquid feeding. Don't use mirror acrylic... it falls apart in a year, in SW.