In-tank ATS design

[tanan]

Ok I dont have much space and extremely clumsy with plumbing so I m trying to get a design that will work in the tank.
I have come with some of the ideas and one I m currently think about is this.Water flow is gonna provided by two 1500lr/hr pumps.
Tank is around 20 G.Lightening will be two PC 6500-6700 bulbs,one plant grow 10000 k light,and one will be actinic(at the front).The max distance between lights and screen will be 4 inches.
The inhabitants will be two false perculas,30 lb or more live rock(mostly DIY).And I m interested into soft corals.
Kindly leave comments so I can further correct it.

[SantaMonica]

It may work; this has not been built before. Would be better to have 3000K bulbs. The actinic and 10k bulbs won't help, so the only light you are getting is from the other ones. The 4" wide screen needs 4 X 35 = 140 gph. Use two layers of very roughed up plastic canvas. And put side-walls on the screen so that all the flow has to go all the way to the end.

Only the parts of the bulbs that are over the screen are going to contribute to growth. So if the bulbs are 24" long, only 18" will get to the scrubber. This would be 18 divided by 24 = 75 percent. If the bulbs are 30" long, this would be 18 divided by 30 = 60 percent.

For a 20g tank, strong filtering would need 20 watts PC over the screen, which is what I'd shoot for with a small tank (I've gone as high as 23 watts on a 5g tank). So if it's two PC bulbs, each one would need to contribute 10 watts over the screen, and if the bulbs are 24" long, this would be 75 percent of a total bulb, which would mean that a total bulb is about 13 watts. So, two 13 watts PC bulbs would work for a 24" wide tank.

[tanan]

Its so great to get comments directly from the guy who inspired me to think of this.
I wont be using any screen as Ill use 4 mm acrylic sheet which will roughed up enough and I choose hanging as it can be easily removed,I just have to take it wash with FW and thats it,no ties no clips etc.
Second I've 2 1000lr/hr pumps,which have duel flow so I guess the top flow will be around 600-700 l/hr.So can I use them ?
I mean 140 gph will be the minimum flow rate.
The canopy will be coated with aluminium film so I guess the reflection will be just perfect.
Now Do I've to change bulbs every 3 months ?
I use chloroform for gluing acrylic is it reef safe ?

[SantaMonica]

You have to use a screen material; plain acrylic, no matter how rough, will fail. It just won't grow anything. Just drill a hole in the acrylic, and use a peg to hold the screen in place on top of it. Two layers, roughed up on all sides.

One of those pumps will be enough.

Yes change the PC bulbs every 3 months; you won't notice a light difference, but the algae will.

Don't know about the glue.

[kcress]

Look at my original Vertical Turf Scrubber build.
http://www.algaescrubber.net/forums/viewtopic.php?f=3&t=98

You will see that acrylic CANNOT be made to work. It's just too slippery for the turf to grip. You will have a very extended initial grown out and the first time you go to clean it almost all the turf comes off. Very disappointing. No matter how much you rough it up. If you need the stiffness for your design that's fine, just affix two layers of roughed up plastic screen on top of it.

[tanan]

Well if the idea is to roughen up then I can show you to how to roughen it up that it ll become 'cactus like'.It wont be translucent but quite opaque!
Paste the highest number of sand paper on a wheel of motor ,such that you can use it on the surface of the screen,It will make it extremely rough in no time but you will need to have atleast 5-6 mm acrylic sheet so that you wont make it paper thin.
I can show you a photo but you to wait for that it is at my uncle's shop(he works with acrylic!).So when I go there next time I will make sure that I can have a pic of that machine.

[SantaMonica]

But it won't be thick. The screen needs to be thick, so that algae can grow inside it. 3 layers of canvas is even better than two.

After you scrape/clean the screen, the only algae remaining to do the filtering will be what is living inside the screen, and if it's just acrylic, that will be zero.

It's not just about surface attachment, it's about living volume.

[tanan]

I never knew that so thanks for telling me.
Now I have to find a screen.

[kcress]

I used hole saws, 20grit sandpaper in a power sander, wire brushes. My acrylic was painful to touch. It made no difference. The chemistry of acrylic is not suitable for turf. Adding a few layers of screen to your acrylic support will certainly do a great job though.

[tanan]

Ok so I finaly made the Hang-on acrylic,here are some pics and its 17 " long and 4.5" wide.Occupies 1/4th of my aquarium wideness.
Now I dont seem to find any screen type plastic material,all I get is clear plastic screens.
And I dont even know what I m looking for (A plastic mesh like ?).

[SantaMonica]

Looks good. Here is the screen:

http://www.everythingplasticcanvas.com/ ... -x-18.aspx (http://www.everythingplasticcanvas.com/pc-20049-260-plastic-canvas-7-mesh-12-x-18.aspx)