Algae Scrubber Basics

[srusso]

Let's keep the Skimmer vs. Scrubber comments to a minimum as past threads show that this creates hostile posts. For this thread let's discuss the algae scrubber as a guild to building and maintaining them. Once the general public knows how to build/keep them and it becomes common knowledge. We can leave it to others threads to compare them.

[frankpayne32]

Originally Posted by srusso

This is incorrect, a screen lit on both sides that is 10x10 has a 100 gallon scrubber capacity.

It is not incorrect. I wasn't commenting on the "capacity" but on surface area. A screen that is 10"x10" does have 200 square inches of surface area if both sides are taken into account. You had it listed as being 100 square inches. I didn't mean anything by it, just thought you'd want to correct an inaccuracy.

[srusso]

Originally Posted by frankpayne32

It is not incorrect. I wasn't commenting on the "capacity" but on surface area. A screen that is 10"x10" does have 200 square inches of surface area if both sides are taken into account. You had it listed as being 100 square inches. I didn't mean anything by it, just thought you'd want to correct an inaccuracy.

Oh! I see! Lol my apologies, let me see if I can get that corrected. Thanks

[Floyd R Turbo]

You are both right.

Frank, I understand what you're getting at because you are correct, a 10x10 screen lit on both sides as 200 sq in of surface area. That begin said, when you are sizing a screen for a system, the "1 sq in / gallon" rule means 1 square inch of screen illumined on both sides. So while technically it is 2 square inches, in ATS terminology it is 1 sq in.

It's just less confusing to say that you need a 10x10 screen for 100 gallons

EDIT:

It's good that you brought that up. If you wanted to get very technical about this process, you would say that you need 2 square inches of illuminated screen for every gallon of system water, and that a screen lit of both sides effectively doubles the filtering capacity of each square inch of screen material. Several people have been confused by that.

Also another point of occasional confusion is the GPH/inch of screen. With a screen that is 2 sided and 10 inches long, the measure to be taken is of the length of the screen, not the length of each side of the screen. So a 10" screen would need 350 GPH not 700, although 350 would be the minimum recommended flow.

You'd be surprised how much water can flow through that 1/8" slot that has a 1/16" thick screen inserted into it, leaving only 1/32' on each side.

[Nova101]

Originally Posted by srusso

Here are pictures of my setup, its a single pump system. Uses four 23w CFL bulbs and I commonly harvest 1 cup of algae.

A nice DIY setup. A question...

How is the top bar of the scrubber attached to your drain? What if you need to replace your PVC? Is the whole thing just suspended by your drain? Weight is not an issue?

Anything else you want to add? Something you might do differently?

[frankpayne32]

Originally Posted by srusso

Oh! I see! Lol my apologies, let me see if I can get that corrected. Thanks

No prob.

Originally Posted by Floyd R Turbo

You are both right.

Frank, I understand what you're getting at because you are correct, a 10x10 screen lit on both sides as 200 sq in of surface area. That begin said, when you are sizing a screen for a system, the "1 sq in / gallon" rule means 1 square inch of screen illumined on both sides. So while technically it is 2 square inches, in ATS terminology it is 1 sq in.

It's just less confusing to say that you need a 10x10 screen for 100 gallons

EDIT:

It's good that you brought that up. If you wanted to get very technical about this process, you would say that you need 2 square inches of illuminated screen for every gallon of system water, and that a screen lit of both sides effectively doubles the filtering capacity of each square inch of screen material. Several people have been confused by that.

Yepp, that's all I was getting at.

[srusso]

Originally Posted by Nova101

A nice DIY setup. A question...

How is the top bar of the scrubber attached to your drain? What if you need to replace your PVC? Is the whole thing just suspended by your drain? Weight is not an issue?

Anything else you want to add? Something you might do differently?

The PVC does hold the screen, and it's never been an issue. The top bar has never been glued in, so it can be removed if needed.

The only thing I would have done differently is started with the additional lighting I added later on.

[BluScrnOdeth]

Lets not forget to mention too that the size of the screen is not only depicted by the size of your tank but also with the quantity/size of the inhabitants inside it. Thats why even though my tank is 300g i made it to support 360. So as my fish population grows or whatever, i can be guaranteed that i have enough surface area to handle the job and to grow with the conditions of my tank.

[widmer]

Glad it's been stickied, cant wait until I can contribute some pictures (although it's going to be a few months out...)

BTW, don't know if anyone has posted this, but the predecessor to this thread can be found here:

http://www.reefcentral.com/forums/sh....php?t=1925996

It's got some great commentary starting on the second page, with PaulB etc.

[salty joe]

Floyd Turbo, that is a very nice scrubber you built.

What is the inside width?
You get 3D growth, right?
Is the aluminum angle heat sink all you need to keep your rig cool? No fans?
Really nice looking scrubber!

[widmer]

Please let me also just reiterate this:

Originally Posted by srusso

Let's keep the Skimmer vs. Scrubber comments to a minimum as past threads show that this creates hostile posts. For this thread let's discuss the algae scrubber as a guild to building and maintaining them. Once the general public knows how to build/keep them and it becomes common knowledge. We can leave it to others threads to compare them.

You can certainly get a taste of the hostility toward ATS that is out there in the first page of the thread I linked to above. In the past there have been lots of threads that have taken a really bad turn for the worse because of this disagreement.

So yes, let's be sure to keep the "which is better" politics out of this thread.

[usefulidiot213]

Great thread! With great info!
One thing I don't understand, is every time there is an algae scrubber thread, question or conversation there is a Skimmer vs. Scrubber brought up. What I don't understand is why you have to have one with out the other. I know some people want to eliminate their skimmers because it takes a lot of natural food from the water column. Aside from that why not run both? Me personally, I will always run a skimmer. However, I see no reason why I can't add an algae scrubber as well. It's only going to help export nutrients and grow pods.

[srusso]

Originally Posted by widmer

Glad it's been stickied, cant wait...

I did a my fair share of begging to get a subforum created for scrubbers, however the forum admins feel RC is segmented enough. So Larry promised me a sticky and here it is...
A real step in the right direction for algae scrubbers!

[hvacman250]

I have a skimmer vs. scrubber question...LOL

My scrubber is on day 3 with a skimmer running. Scrubber screen is white as a ghost. Scrubber site said I should see something by day 3.

Is the skimmer running preventing algae from growing on my screen? Or am I being impatient? It's like watching grass grow over here

Edit: my set-up again:

40 BR, ATS lit on ONE side, so I did 8" W x 12" long = 96 squareinches
2 26W CFLs in a dome reflector, 4-5" from surface = 52 W
Powered by a MaxiJet 1200 = 296 GPH
Pump non-stop, light 18 hrs on, 6 off.

[BluScrnOdeth]

Originally Posted by hvacman250

I have a skimmer vs. scrubber question...LOL

My scrubber is on day 3 with a skimmer running. Scrubber screen is white as a ghost. Scrubber site said I should see something by day 3.

Is the skimmer running preventing algae from growing on my screen? Or am I being impatient? It's like watching grass grow over here

Edit: my set-up again:

40 BR, ATS lit on ONE side, so I did 8" W x 12" long = 96 squareinches
2 26W CFLs in a dome reflector, 4-5" from surface = 52 W
Powered by a MaxiJet 1200 = 296 GPH
Pump non-stop, light 18 hrs on, 6 off.

I would honestly give it 7 days. If you still see nothing take off the Skimmer. The way a scrubber works is by removing the byproducts of broken down proteins which your Skimmer is removing before they break down. Though its unlikely its doing it 100% and some algae should grow.

Also with the specifics of your setup, you could try putting your lights exactly 4" from the screen. Just be sure if you remove the skimmer you monitor water quality to be safe.

[srusso]

Here is word from the one and only SantaMonica himself....

"I'd remove the velcro part.

Also it might be more clear if you changed

2 sq. inches of screen per gallon, if lit on just ONE side.
(10 x 10 = 50 sq. inches = 50 gallons)
(Horizontal) - (can only be lit from one side, for obvious reasons)
4 sq. inches of screen per gallon
(10 x 10 = 40 sq. inches = 40 gallons)

...to this:

2 sq. inches of screen per gallon, if lit on just ONE side.
(10 x 10 = 100 sq. inches = 50 gallons)
(Horizontal) - (can only be lit from one side, for obvious reasons)
4 sq. inches of screen per gallon
(10 x 10 = 100 sq. inches = 25 gallons)

Otherwise looks great!

Lastly, if you could get www.radio-media.com/fish/AlgaeScrubbers.doc listed on the stick, it might be easier for new folks to understand."

[srusso]

Originally Posted by hvacman250

I have a skimmer vs. scrubber question...LOL

My scrubber is on day 3 with a skimmer running. Scrubber screen is white as a ghost. Scrubber site said I should see something by day 3.

Is the skimmer running preventing algae from growing on my screen? Or am I being impatient? It's like watching grass grow over here

Edit: my set-up again:

40 BR, ATS lit on ONE side, so I did 8" W x 12" long = 96 squareinches
2 26W CFLs in a dome reflector, 4-5" from surface = 52 W
Powered by a MaxiJet 1200 = 296 GPH
Pump non-stop, light 18 hrs on, 6 off.

Your skimmer will have little impact on your scrubber. That said a picture may help us Figure out what maybe wrong... But as you said it's only been 3 days. Understand that you "could" see growth in as little as 3 days... For most of us the first 2 weeks are like watching paint dry. If it's built correctly and you have fairly clean water you should see the littlest bit of green growth on the 7th day. Clean it off anyway and repeat in 7 days again.

[bucks448]

I hit the 5 day mark with mine yesterday and just started to notice a spec of green here and there. I also am still running my skimmer and I have my sock in place still. +1 to give it more time.

[KafudaFish]

Can you explain on the horizontal vs. vertical, one side lit why the number of gallons is reduced by half on the 10 x 10 screen (50 vs. 25)?

Thanks.

[srusso]

Originally Posted by bucks448

I hit the 5 day mark with mine yesterday and just started to notice a spec of green here and there. I also am still running my skimmer and I have my sock in place still. +1 to give it more time.

And thats a good point! If your main filtration has been a skimmer DO NOT, repeat DO NOT remove it from your system until your scrubber has matured! This will take at least 2 - 3 months! (you could be ready before this but this is a safe time length before removing a skimmer)

if that is what your end goal is to do, replace your main filtration.

And this is only true if your scrubber has been built correctly.
Please understand your tank always remains your responsibility!

[srusso]

Originally Posted by KafudaFish

Can you explain on the horizontal vs. vertical, one side lit why the number of gallons is reduced by half on the 10 x 10 screen (50 vs. 25)?

Thanks.

B/c only one side of your screen can be lit when your screen is horizontal, which means half of the growing surface.

[KafudaFish]

Ok thanks for answering my question. I will chew it over on the way home.

[miguelp19]

woop! congrats on the sticky! im excited cuz now it'll be a little easier to find info on ATS. Im planning on changing my filtration from PS to ATS but in a few months. For now, i will follow along and absorb as much as possible. Thanks to all the gurus for the info and time put in to helping us newbs.

[srusso]

B/c there is a lot of info around the net on algae scrubbers don't be surprised if two gurus have different methods of running ATS. This sticky is to hopefully gather the options together and come up with a basic guild line for running one.

[bucks448]

Originally Posted by srusso

B/c only one side of your screen can be lit when your screen is horizontal, which means half of the growing surface.

I think the question was two part...

A vertical scrubber's effectiveness with lighting only on one side is reduced by 50%, so you need to double the size of the screen so you can light the same amount of square inches as a double sided scrubber.

I believe horizontal scrubber's effectiveness is reduced even more because of the water flow and surface area exposed to the air, so you need 4 times the surface area of a double sided vertical scrubber.

When I was building mine I was really considering either a single side or horizontal scrubber because of space constraints. It was stress to me to go with a double sided scrubber.