Algae Scrubber size, wattage and flow calculator

[SantaMonica]

Courtesy of user CDM2012:
https://public.sheet.zoho.com/public/cdm2013/ascalculator-xls-1

[Floyd R Turbo]

Pretty slick

[Devs]

Nice ! :)

[varke]

works good.
My ats is 55 watt pl with 50 cm X 7 cm screen with 4 bloks feeding and the calculator had the same numbers.

[cdm2012]

:) Thx

[sklywag]

That is very cool.

[djmatteo]

I am a little confused about screen size, if the calculator says I need 36 sq inches is that 36 if lit one side and 18 per side if lit 2 sides? The screen size calculator isnt very clear, I assume its actually calculating based on 1 sided screens but I want to make sure I do this proper before I go any further with my rebuild.

[cdm2012]

I am a little confused about screen size, if the calculator says I need 36 sq inches is that 36 if lit one side and 18 per side if lit 2 sides? The screen size calculator isnt very clear, I assume its actually calculating based on 1 sided screens but I want to make sure I do this proper before I go any further with my rebuild.

36 sq. in. whether it is lit on one side or two

[Devs]

hehe ! I've had this same ding dong with SM over on UR and the conclusion was...

Lets say you're feeding one cube per day, that would make a single sided screen 24" square of say 4" x 6" and lit by four 3watt leds. Now...if that screen were to be lit from both sides (Two 3watt leds either side) it would make it a 2 sided screen with double the filtration capacity, so...a 2 cube feed per day.

Having said all that...I prefer to do it similar to the way floyd has....6 reds and 2 blues with a current divider on the blues and use a prismatic diffuser over the leds for an even light spread.

[cdm2012]

An example VERTICAL upflow or waterfall screen sized to 1 cube of feeding is 3 X 4 inches = 12 square inches of screen (7.5 X 10 cm = 75 sq cm). If using cfl's, you would need 1-watt per sq. in. That would be a total of 12 watts. So if you want all the lights on one side the screen size would stay the same size. You don't double the screen size if putting lights on one side only. You just put the total wattage one side or you cut the wattage in half for 2 sides.

So, using the example of 1 cube above, if you want to light it on both sides you would cut the total wattage in half. 6 watts on one side and 6 watts on the other for a total of 12 watts. Or you would light it on one side with 12 watts, but it would still be 12 watts total on the 12 sq. in. screen.

If you are going to use LED's, SantaMonica recommends that you only need half the wattage of a cfl which would be 6 watts. If you want to have 2 sides then 3 watts on one side and 3 watts on the other for a total of 6. Or you can go 6 watts total on one side only.

The calculator is based on Santamonica's recommendations.

Updated the calculator. Seems there was an error on my part

I know Floyd and others have modified ways of doing LED's and maybe I'll add those modifications to the calculator in time.

[Floyd R Turbo]

The rule has always been a single sided screen is 1/2 the capacity of a 2 sided screen. If you have 12 sq in of 2-sided, lit appropriately, it is a 1 cube/day screen. You need the same physical surface area and light for a single sided screen, meaning 24 sq in with the same amount of light but all on one side. Taking a 12 sq in screen and putting all the light on one side does not keep it at a 1 cube/day scrubber - you would just have a higher-intensity 1/2 cube/day scrubber, which might get you a little more scrubbing power than 1/2 cube, but not quite double

unless some guideline has changed again...

[Devs]

Exactly right Floyd...at last a none convoluted political answer much the way I would have put it myself.

[cdm2012]

Ok. Re-check the calculator and see if it's correct now.

[rygh]

Fun spreadsheet!
An interesting addition would be to add a few driver current selections into LEDs.
For example, 700 mA driver and 350 mA drivers.


Also, a "3 watt" LED is not particularly accurate anyway, and a bit confusing.
Those are really for cool-white. The deep reds are not 3 Watts.
A Luxeon Rebel 660nm at 700mA = 2.4Vf = 1.7 Watts. And 700 mA is the max current.
At 350 mA = 2.2Vf = 0.77 Watts

[Floyd R Turbo]

Yes but for purposes of scrubber light fixture sizing, we use the term 3W. I have mentioned this in other thread that 3W is used basically for marketing purposes so let's not confuse everyone. Otherwise we'll have people buying 2W LEDs (which are available also)