Need help building ats.

[jreef]

Hi,
I have just become a member to this site, I have been keeping marines since december 2010.
I have done a fair amount of reading on algae scrubbers and have been very interested in setting one up but never got round to it.
My system has a 270liter display and 65liter sump. I currently run a skimmer with reverse lit cheato along with 30kgs of live rock.
Although my system has always had low nitrate and phosphate I have started to get some algae issues and want to get this under control.
I am undecided on whether to run it off the single 32mm durso drain or get a pump to run it on. I would hope I can run it off the drain as it would be cheaper to build/run.
The only disadvantage I can see is what if the slot in the pipe gets blocked? How can this be overcome to prevent a flood? I am also a bit tight for space due to the way my sump is designed and skimmer.
With the flow going through the drain I would imagine it is around 1800-2000lph, I have an eheim compact 3000 as a return but obviously I would need to accurately measure this.
Anyway thanks for reading and any help would be greatly appreciated.

Hopefully a fts above, an old one.

[jreef]

Does anyone run a scrubber off the drain to the sump? Do I need to worry about the pipe getting blocked?
Thanks.

[kotlec]

Does anyone run a scrubber off the drain to the sump? Do I need to worry about the pipe getting blocked?
Thanks.

Many run. Just make another emergency elevated pipe outlet in case your ATS drain will get blocked.

[MorganAtlanta]

Absolutely measure your flow before you build a scrubber on the drain. You may have much less flow than you think.

[jreef]

Thanks for the replies,
After some thinking I believe it may be easier to run it off a pump due to space restriction around the drain.
So, a few more questions if I may.
My tank including sump has a total of 330liters (72gal or 87USgal).
When constructing an ATS, do you use the total volume or just the display volume?
Going on the above liters I have worked out I need a screen of 9inch by 9inch, is this correct?
I have brought a new jet 1700lph pump which will hopefully give me 1200lph over the screen, is this correct for the width?
Also I intend to light it by a single lamp either side, would a 30watt 6500k with reflector be suitable for this? or less if possible?
As I am now going to use a pump do I need to have any measures in place in case the slot gets blocked, or is it ok if the pipework only has the slot and an end cap on the end of the pipe?
Thanks in advance.

[SantaMonica]

Scrubber Size Guideline, using feedings:

An example vertical waterfall screen size is 3 X 4 inches = 12 square inches of screen (7.5 X 10 cm = 75 sq cm)with 12 real watts (not equivalent) of fluorescent light. If all 12 watts are on one side, it is a 1-sided screen. If 6 watts are on each side, it is a 2-sided screen. This screen size and wattage should be able to handle the following amounts of daily feeding:

1 frozen cube per day (2-sided screen)
1/2 frozen cube per day (1-sided screen)
10 pinches of flake food per day (2-sided screen)
5 pinches of flake food per day (1-sided screen)
10 square inches (50 sq cm) of nori per day (2-sided screen)
5 square inches (50 sq cm) of nori per day (1-sided screen)
0.1 dry ounce (2.8 grams) of pellet food per day (2-sided screen)
0.05 dry ounce (1.4 grams) of pellet food per day (1-sided screen)


Scrubber Size Guideline, using gallons:

1.0 real (not equivalent) fluorescent watts per gallon [0.26 watts per liter].
1.0 square inches of screen per gallon, with bulbs on BOTH sides (10 x 10 = 100 square inches = 100 gal) [1.64 square cm per liter]
2.0 square inches of screen per gallon, if vertical but lit on just ONE side. [3.28 square cm per liter]
4.0 square inches of screen per gallon, if HORIZONTAL [6.56 square cm per liter].
1.5 real (not equivalent) fluorescent watts per gallon if HORIZONTAL [0.4 watts per liter].
18 hours of lights ON, and 6 hours of lights OFF, each day for HIGH filtering. Less hours for MEDIUM filtering.
Flow is 24 hours, and is at least 35 gph per inch of width of screen, EVEN IF one sided [60 lph per cm].
Very rough screen made of roughed-up-like-a-cactus plastic canvas.
Clean algae off of screen every SEVEN (7) days.

[jreef]

Thanks for the reply,
So my lights need to be more like 40watt each side.
I take it when we are talking about gallons we are using US gallons?
If I build my screen 9inchx9inch it would be correct for my total tank volume with 1200lph of flow and 40watts of fluorescent light each side, however I only have a few fish at the moment that only get fed the equivalent of 1/2-1 cube a day which a screen of 3x4inches would handle. Would a full size (9x9) screen have enough food to keep it growing?
Thanks.

[SantaMonica]

The larger screen would just not grow very thick. But it would be able to handle much much more food.