Building Your Own Algal Turf Scrubber (ATS)

[chicago]

i have something very similar.. and is working nicely. my algea though is more slim like but one it got going really produces a lot. i added it to one of my un- used sections of my pre sump . CF Grow Lights from Amazon. work well. Hot though and need to remove Rust Potential screws ect.

 

[chicago]

I use to have two in there for each side but found that one works fine..

 

[chicago]

to be clear.. i use to have one single and the double. one double as shown operating has been enough.

 

[Feet4Fish]

@ca1ore Still going strong? Like your light choice. 150 w the sweet spot. Getting ready to start my build! Thanks!

 

[Feet4Fish]

One more question. I know you said surface area of screens needed is based on cubes fed daily. But in all your experience what is a good rule of thumb?? How big versus how many cubes?

 

[ca1ore]

@ca1ore Still going strong? Like your light choice. 150 w the sweet spot. Getting ready to start my build! Thanks!

Yeah, good so far. 150 watt LED equivalent was a much better choice than the 300, which I returned LOL. Growstar is less purple than prior lights I have used, but is growing algae like gangbusters.

 

[ca1ore]

One more question. I know you said surface area of screens needed is based on cubes fed daily. But in all your experience what is a good rule of thumb?? How big versus how many cubes?

Haha, I think you'll get a whole lot of different views on that. Here's mine …… I personally have found that the accepted guidelines are a bit too low, in other words I need more surface area per cube equivalent that the recommendation. I feed about 12 cube equivalents daily and the current screen is 480 square inches (counting both sides) with all screen area growing algae; so that's 40 square inches per cube. Another way to 'size' is to use 1 square inch double lit per gallon of water.

 

[Feet4Fish]

Haha, I think you'll get a whole lot of different views on that. Here's mine …… I personally have found that the accepted guidelines are a bit too low, in other words I need more surface area per cube equivalent that the recommendation. I feed about 12 cube equivalents daily and the current screen is 480 square inches (counting both sides) with all screen area growing algae; so that's 40 square inches per cube. Another way to 'size' is to use 1 square inch double lit per gallon of water.

Perfect! That is so useful info to know. Will start my build this week hopefully. Whenever scrolling through R2R i always stop on your and a handful of other la posts! Really value your insight and experience.

 

[jorahx]

whats better, high flow of water or low?

 

[Feet4Fish]

whats better, high flow of water or low?

In my opinion flow needs to be adequate to distribute evenly across the screen. So if you made me call one side or the other I would do more with low flow. But there must be enough adjustability to dial-in the flow to evenly distribute across the screen.

 

[Scrubber_steve]

Perfect! That is so useful info to know. Will start my build this week hopefully. Whenever scrolling through R2R i always stop on your and a handful of other la posts! Really value your insight and experience.

Keep in mind, when designing a scrubber the standard for screen size is 12 square inches per cube equivalent, & that is not 12 square inches per side, it is 12 square inches total. So if you were feeding 4 cube equivalents per day your screen would be 12" x 4", or 6" x 8", or whatever dimensions equal a total of 48 square inches.
I have found the 12 square inches per cube equivalent rule to be accurate but keep in mind that the length of the photo period, & the light intensity affects the rate of photosynthesis, & therefore the rate of inorganic nutrient export. Intensity wise, you need around 0.25W to 0.5W per inch of screen each side, & that's actual watts.Too higher wattage can result in photo-inhibition.

If a scrubber is the only filtration method used for inorganic nutrient export (besides live rock) then you will need to increase the screen size, maybe double it.
You 're right about flow rate. All that is needed is a flow fast enough to fully cover the entire screen without channelling. Any faster than that will not increase inorganic nutrient export further, & some people say too fast a flow can be negative.

 

[Feet4Fish]

Keep in mind, when designing a scrubber the standard for screen size is 12 square inches per cube equivalent, & that is not 12 square inches per side, it is 12 square inches total. So if you were feeding 4 cube equivalents per day your screen would be 12" x 4", or 6" x 8", or whatever dimensions equal a total of 48 square inches.
I have found the 12 square inches per cube equivalent rule to be accurate but keep in mind that the length of the photo period, & the light intensity affects the rate of photosynthesis, & therefore the rate of inorganic nutrient export. Intensity wise, you need around 0.25W to 0.5W per inch of screen each side, & that's actual watts.Too higher wattage can result in photo-inhibition.

If a scrubber is the only filtration method used for inorganic nutrient export (besides live rock) then you will need to increase the screen size, maybe double it.
You 're right about flow rate. All that is needed is a flow fast enough to fully cover the entire screen without channelling. Any faster than that will not increase inorganic nutrient export further, & some people say too fast a flow can be negative.

Thank you for your input. You Made some great points definitely I need to factor in. Decided to take on this project because after 15 years in the hobby this seems like DIY project that I can handle. The other main reason is then when I looked at commercial units that would accommodate my system size everything I found has been north of $700. Information like what you and ca1ore provide is truly invaluable to me.

 

[ihavecrabs]

Nice article @ca1ore

 

[Feet4Fish]

Thank you for your input. You Made some great points definitely I need to factor in. Decided to take on this project because after 15 years in the hobby this seems like DIY project that I can handle. The other main reason is then when I looked at commercial units that would accommodate my system size everything I found has been north of $700. Information like what you and ca1ore provide is truly invaluable to me.

I have a question to pose. Does it matter whether you increase area by making the screen longer versus taller. For example 36 x 12 versus 12x36?

 

[Scrubber_steve]

I have a question to pose. Does it matter whether you increase area by making the screen longer versus taller. For example 36 x 12 versus 12x36?

The wider the screen, the larger the water pump needed.

 

[Feet4Fish]

The wider the screen, the larger the water pump needed.

Understood but no increased biological benefit with either orientation?

 

[Scrubber_steve]

Understood but no increased biological benefit with either orientation?

No. Width v length, on it's own, will make no difference, as long as an even coverage of water & light is maintained in either scenario.

 

[Feet4Fish]

Perfect. Thanks! Definitely building my own as there just aren’t well designed reasonable priced commercial size units available.

 

[ca1ore]

There are not, I agree ….. thus the article

 

[hyla84]

After reading your guide a I am planning to built one as well.
I have a 400 liters tank.
How big would it be the canvas for my thank?
So I can plan the dimensions of the entire box
Thanks [emoji16]