Algae Scrubber Basics

[XSiVE]

Originally Posted by Floyd R Turbo

Yeah I've been meaning to get some of that stuff together, it's on my list of a million things to do when the wife and kids and work don't take up all my time.

xsive, what is your flow in GPH/in, tank specs, water parameters, screen dims, light specs & reflector, etc

Display is 120gal, screen is about 12" wide by about 12" tall (outside of the water line that you can see in the pic), lighting is currently 3x 23W 2700k CFL's with 8.5" reflectors, two on one side one on the other which is all I can fit with the current config.

I have the scrubber actually running off the overflow of my 10g frag tank which is plumbed into the same sump as the display. I calculated the GPH/inch at about 25 which I know is a little lower than typical but since it runs off the overflow it seems to surge a little bit which seems to make up for the slightly lower flow rate.

Water parameters for N and P, im not sure as I recently threw away my test reagents as they were well beyond expired. I know it's working a little as the GHA in my display is starting to brown and die in places.

[Floyd R Turbo]

I am going to be running an experiment to try and determine what works best. I currently have 2 custom fixtures being made and will be able to use those to test almost a dozen combinations of red, deep red, blue, and royal blue.

For now, if you're going to DIY it, most have had good results from 630nm red and a few have said that 660nm Deep Red works great.

[Floyd R Turbo]

Originally Posted by XSiVE

Display is 120gal, screen is about 12" wide by about 12" tall (outside of the water line that you can see in the pic), lighting is currently 3x 23W 2700k CFL's with 8.5" reflectors, two on one side one on the other which is all I can fit with the current config.

I have the scrubber actually running off the overflow of my 10g frag tank which is plumbed into the same sump as the display. I calculated the GPH/inch at about 25 which I know is a little lower than typical but since it runs off the overflow it seems to surge a little bit which seems to make up for the slightly lower flow rate.

Light is a little low and flow is too, but as long as your nuisance algae is not a problem and your N and P are low, who cares?

Originally Posted by XSiVE

Water parameters for N and P, im not sure as I recently threw away my test reagents as they were well beyond expired. I know it's working a little as the GHA in my display is starting to brown and die in places.

That's the key. If it works, you can see the results. Even if you don't build it 100% right, it will still do something, it may no be able to handle a full bioload and heavy feeding, and it may not be able to battle a bad cyano problem, but it's still very effective.

[Rabidgoose]

XSIVE;

Can you point me toward pictures of your scrubber or post some if their are none. We have similar size requirements it seems.

thanks........chuck

[TheHoove]

Originally Posted by Floyd R Turbo

I am going to be running an experiment to try and determine what works best. I currently have 2 custom fixtures being made and will be able to use those to test almost a dozen combinations of red, deep red, blue, and royal blue.

For now, if you're going to DIY it, most have had good results from 630nm red and a few have said that 660nm Deep Red works great.

Its interesting, I have a couple spots of hair algae still in my tank on the return and in the overflow, and it hasent slowed down any since switching from my old pc lights to my leds. My leds are 2r royal blue, 14 neutral white, 5 cool white, 5blue. so im guessing most combination would grown the algae. But not sure the most efficient. PaulB added a led strip over his algae trough. wonder how his growth is doing?

[PowermanKW]

Originally Posted by Floyd R Turbo

Horizontal scrubbers are not as effective and really only work well if you have a surge type of setup. Horizontal screens that are constantly submerged do not work well at all. Also you need 1.5W per square inch, minimum, and must have reflectors. You have 36W over 98 square inches which is 0.36 W/sq in.

Horizontal surge/dump scrubbers have a tendency to grow red turf algae, which is not as effective as vertical waterfall style scrubbers. This is why I don't recommend horizontal scrubbers - they're fraught with the problems of the past.

So is there anyother problems with horizontal scrubbers besides the ones listed. Do you have some examples of ones that didn't work out well?

[Floyd R Turbo]

The original dump-bucket style scrubber has moving parts, makes noise, can splash, when the turf is exposed is smells, they're bulky, large, and expensive. You can buy them from Inland Aquatics and they pay a royalty to Adey I believe (one of the reasons they are expensive) so you can't really get them made anywhere else to my knowledge. Very early on in this thread there is a nice example of one someone built that makes a nice surge in their tank though, so they're not completely horrible, just much more complex and difficult to build.

If you don't go with a dump-style, then it's easier, but you still have a lot of horizontal space requirement. The screen needs to be double the size that it needs to be for a comparable vertical scrubber, so if you have a 100g tank you would normally need a double-lit vertical screen 100 sq in (L x W), for one lit on only one side it would need to be 200 sq in (L x W), and for horizontal you need 400 sq in (L x W). Then it needs 50% more light because you need to spread it out more to cover the area, and then you're still running it at a lower watt/sq in.

Horizontal non-dumping screens also have a tendency to 'channel', where the algae will grow thick and divert water around it, leaving pockets of stagnant water that will have nearly zero flow and no boundary layer flow to speak of, which all but eliminates filtration in those areas. Slanted screens have a little less of this, but it is still there.

These are all the issue of the past that really made algae scrubbers ineffective. That and poor lighting, that's a big one.

So if you're going to make a horizontal scrubber, the key is to at least try to incorporate some kind of surge device, perhaps a constant low flow to keep the algae covered and help keep the smell down and a surge box to dump at regular intervals, and over-light the snot out of it.

[terahz]

Ok, so after reading the summary, you guys are saying that all I need on my 40B is a 6"x7" double sided screen? A couple of red and a blue CREEs on each side and call it a day? That sounds too simple

On LEDs: the green algae in my tank seem to have no trouble growing on CW/RB mix, just saying

You guys should really push for a reefcentral WIKI! going through hundreds of pages of posts is a pita.

[Floyd R Turbo]

Originally Posted by terahz

Ok, so after reading the summary, you guys are saying that all I need on my 40B is a 6"x7" double sided screen? A couple of red and a blue CREEs on each side and call it a day? That sounds too simple

On LEDs: the green algae in my tank seem to have no trouble growing on CW/RB mix, just saying

You guys should really push for a reefcentral WIKI! going through hundreds of pages of posts is a pita.

You want heavy red and hardly any blue, if any at all. One LED build used RB/WW and grew almost nothing, then switched to all Deep Red and he has to clean every 3 days. Trust my when I say, do not use CW, NW or RB on a scrubber. You need lots and lots of red.

The jury is still out on what red works best and what blue also (because it's never really been bench tested)

The other issue with LEDs is spotty growth since it's difficult to spread 3W crees, so you're right it's just not that simple.

[terahz]

Originally Posted by Floyd R Turbo

You want heavy red and hardly any blue, if any at all. One LED build used RB/WW and grew almost nothing, then switched to all Deep Red and he has to clean every 3 days. Trust my when I say, do not use CW, NW or RB on a scrubber. You need lots and lots of red.

The jury is still out on what red works best and what blue also (because it's never really been bench tested)

The other issue with LEDs is spotty growth since it's difficult to spread 3W crees, so you're right it's just not that simple.

I was partially joking about the CW/RB as my rocks look like turf scrubbers at the moment .

But yeah, that's why I said red and blue. Basically green algae have both chlorophylls a and b (if this book is to be believed). And if this is to be believed their light absorption peaks are in the areas of 430nm and 665nm for A and 460nm and 645nm for B.

From CREEs datasheets: XPE royal blue is at 465nm (I guess as close as it gets to the 430-460nm range) so all we need is a decent red - a little bit broader spectrum - (cree's reds are peaking at 630nm and is at only 10% intensity at 650nm so basically useless) and we're all set Anyone know of a red LED that is shin king in the 630-670nm range?

Anyway, I haven't really read the entire thread so maybe I'm repeating things that have been said before, if so I apologize.

[rysher]

Originally Posted by terahz

Ok, so after reading the summary, you guys are saying that all I need on my 40B is a 6"x7" double sided screen? A couple of red and a blue CREEs on each side and call it a day? That sounds too simple

On LEDs: the green algae in my tank seem to have no trouble growing on CW/RB mix, just saying

You guys should really push for a reefcentral WIKI! going through hundreds of pages of posts is a pita.

that is what i have (almost), i have a 6x9 screen, 1 inch is submerged so only 6x8 is really used, i also have a 40b

it has been my only form of filtration ever since i started the tank last February, i feed almost 2 cubes a day, only have 2 fishes but u cant see any algae on my DT, almost non existent film algae too, i clean my DT glass maybe once a week.

[srusso]

Originally Posted by terahz

Ok, so after reading the summary, you guys are saying that all I need on my 40B is a 6"x7" double sided screen? A couple of red and a blue CREEs on each side and call it a day? That sounds too simple

On LEDs: the green algae in my tank seem to have no trouble growing on CW/RB mix, just saying

You guys should really push for a reefcentral WIKI! going through hundreds of pages of posts is a pita.

Yet another member of the local reef club gives in... ;-)

Resistance is futile... Hahaha

Happy to help any way I can, although, compared to others... I am not greatest scrubber builder. Still tweaking my crappy ghetto build... But that maybe mostly due to the wallet being empty way too often...

[terahz]

rysher, that's great. I hope it works for you long term as well.

Originally Posted by srusso

Yet another member of the local reef club gives in... ;-)

Steve, don't claim victory just yet, I haven't said I'll be doing one . I was just reading for general knowledge and surprised at how small ATS needs to be enough for my tank.

Regardless, keep up the great work.

[zhewitt04]

Question!? Starting a new scrubber.... Version 3.0. I was curious to the lights. I am thinking of going with a 15 x 15 screen horizontal. The reason for the horizontal is to save money on one T5 light fixture. I was curious to amount of time between changing bulbs for a ATS. I know you are supposed to change bulbs very 12 to 18 months on your display or you get algae growth in your tank. So do I want to use older bulbs on you scrubber to promote algae growth? Also what are the disadvantages to a horizontal? Like I said it think it would be cheaper and since space is not a promblem for me, horizontal seems the way to go.
Also what angel do i want to put the scrubber at? Does it matter? I was going to use a piece of acylic with some sides coming up to keep the water in the container and then have it empty into a filter sock so i don't have any loose pieces exscaping into the sump or display.
Thinks for all the help in advacne and I am open to any suggestion..... o I am also using a overflow box its rated at 600 gallons a hour or should I go with the bigger 1200 gallon a hour box?

[PowermanKW]

Originally Posted by Floyd R Turbo

The original dump-bucket style scrubber has moving parts, makes noise, can splash, when the turf is exposed is smells, they're bulky, large, and expensive. You can buy them from Inland Aquatics and they pay a royalty to Adey I believe (one of the reasons they are expensive) so you can't really get them made anywhere else to my knowledge. Very early on in this thread there is a nice example of one someone built that makes a nice surge in their tank though, so they're not completely horrible, just much more complex and difficult to build.

If you don't go with a dump-style, then it's easier, but you still have a lot of horizontal space requirement. The screen needs to be double the size that it needs to be for a comparable vertical scrubber, so if you have a 100g tank you would normally need a double-lit vertical screen 100 sq in (L x W), for one lit on only one side it would need to be 200 sq in (L x W), and for horizontal you need 400 sq in (L x W). Then it needs 50% more light because you need to spread it out more to cover the area, and then you're still running it at a lower watt/sq in.

Horizontal non-dumping screens also have a tendency to 'channel', where the algae will grow thick and divert water around it, leaving pockets of stagnant water that will have nearly zero flow and no boundary layer flow to speak of, which all but eliminates filtration in those areas. Slanted screens have a little less of this, but it is still there.

These are all the issue of the past that really made algae scrubbers ineffective. That and poor lighting, that's a big one.

So if you're going to make a horizontal scrubber, the key is to at least try to incorporate some kind of surge device, perhaps a constant low flow to keep the algae covered and help keep the smell down and a surge box to dump at regular intervals, and over-light the snot out of it.

Thanks a bunch. For once in my life I asked why I should not reinvent the wheel instead of learning myself.

I have actually thought of channeling, which is why I thought about a deeper trough. Had not thought about smell. However, never thought about the air water interface. So to give some surface area as you mention... then the trough just gets longer and longer... plus to be space efficient, it needs to go back and forth... so the only way would be to surge... but then that surge is not going to be so great farther down the trough and going around some "U" bends, not to mention the algae itself slowing it.... I see what you mean.

The surge device never appealed to me... at least not on a display tank. Yes cool, but lots of problems. Possibly on a scrubber in a fish room, not sure. Thought about slants... even thought about up flow over flows... say you have a inlet drain to a tank pass water under a baffle... up flow it say in a 3" space put the screen 1" below th water... let it up flow through the screen and algae and then overflow to next chamber and baffle and do it again. Sounds good, but perhaps I could not be certain of even flows after a lot of baffles, and then we are back to that surface area total again....

Well designs get filters down to best bang for buck, and it seems the vertical screen has the most advantages. Still easy to do in a the sort of system I want to do.. fish room, a couple of tanks for stuff, small display tanks, large water volume. I realize you do not want to get into comparisons, but I would have to crunch some number to see what kind of power I would be using over other ways to get low nutrients... although, lowest power use and low nutrients are not the only factors.. I really want a strong micro fauna food chain.

[gark666]

Originally Posted by srusso

Yellow indicates low nutrients, normally caused by lack of flow, lights too intense or bad placement. Some times it means the tank is not being fed enough food... Let's see some pictures and details about your setup.

Here is my set up the screen used to be 12x12 and I trim it down to 10x8 like you suggested I also change the bulbs from 23watt 27000k flood lights to 40watt 27000k CFL lights with 8" reflectors, the lights are 4" away from the screen for flow a have a cheap knock off a rio 1400 which is about 400GPH I already clean up the screen 3 time and the only thing that still growing is yellow slime alge also i feed the tank once a day before the lights turn off!

[srusso]

Originally Posted by gark666

Here is my set up the screen used to be 12x12 and I trim it down to 10x8 like you suggested I also change the bulbs from 23watt 27000k flood lights to 40watt 27000k CFL lights with 8" reflectors, the lights are 4" away from the screen for flow a have a cheap knock off a rio 1400 which is about 400GPH I already clean up the screen 3 time and the only thing that still growing is yellow slime alge also i feed the tank once a day before the lights turn off!

More flow should help, that 400 what the advertised flow is?

You chould start feeding in the mornings as well. What is your bio load? Fish really need a few feedings a day. I plan to get a nice auto feeder this Christmas.

If you can't feed more you can start cutting the time the scrubber lights are on... Floyd knows much more on the subject then I do, but I know it was posted in the last 100 posts or so...

[SPotter]

This weeks cleaning update......moved the leds back as far as they could go as well as stagger them on each side. Big improvement in color and growth.

Last weeks cleaning





This weeks....




I cut the pipe down to 8" and widened my slot just a little bit tonight. We will see how that works next week when I clean the screen.


Steve

[tsharp90]

I put up scrubber and for about 2 weeks had nothing but diatoms growing on it. Nitrates were about 20ppm. I bought some chaeto from lfs and draped it over the scrubber. Over a few days Nitrates dropped to 5 which is where I want it for my nems. I took off the cheato and threw it in sump and discovered some green growth had started on the screen. Nitrates are now reading zero which I would like to raise.

110 gal tank with 2 snowflake eels 3 damsels and 3 btas. I feed nems and damsels twice a day, eels every other day. I don't have a protein skimmer. I do have sort of a dsb in my sump but half the sand has dissolved and i need to buy more.

Found this thread right as I was dreading having to buy a new skimmer. Im glad I did. Thanks guys.

[gark666]

Originally Posted by srusso

More flow should help, that 400 what the advertised flow is?

You chould start feeding in the mornings as well. What is your bio load? Fish really need a few feedings a day. I plan to get a nice auto feeder this Christmas.

If you can't feed more you can start cutting the time the scrubber lights are on... Floyd knows much more on the subject then I do, but I know it was posted in the last 100 posts or so...

Yeap it says 400 gph and as for the bio load I have:

1 Sailfin tang
1 blue tang
1 lawn mower bleny
1 royal grama
2 false perculas
7 tridacna clams
1 5" ritteri anemone
A bunch of sps and lps

[rysher]

how do you get nitrates?

[srusso]

Originally Posted by gark666

Yeap it says 400 gph and as for the bio load I have:

1 Sailfin tang
1 blue tang
1 lawn mower bleny
1 royal grama
2 false perculas
7 tridacna clams
1 5" ritteri anemone
A bunch of sps and lps

How is it fed? Directly to your scrubber? Or is it your return pump, and the scrubber being fed through the over flow?

Yeah tangs need lots of food... so you feed once a day at the moment, how much food?

7 clams?! Nice let's see!!

[Floyd R Turbo]

Originally Posted by rysher

how do you get nitrates?

calcium nitrate here: http://www.aquariumfertilizer.com

[salty joe]

Originally Posted by Floyd R Turbo

I am going to be running an experiment to try and determine what works best. I currently have 2 custom fixtures being made and will be able to use those to test almost a dozen combinations of red, deep red, blue, and royal blue. .

That's exciting. Any idea when you'll get this thing going? I was wondering about LED scrubbers, rather than move the LEDs farther away, wouldn't it be more energy efficient to turn them down and leave them point blank with a diffuser? Also, would increasing the flow allow the LEDs to be closer? I know you've wanted to do this for awhile and I appreciate you doing this. Can't wait to see some results. Thanks.

[TheHoove]

Ok so today was week 4 cleaning, plus one day. I had a small amount of green algae. Mostly Brown. I'm getting some hair algae kicking up in the tank in small spots here and there, So i know there is some amount of nutrients in the tank. So I cut the screen down to 7". Its now 7x10" lit. That puts me at least 35gpm per inch, but likely more, as that measurement was before taking about 2' out of the return and cleaning the pump. I got my lights a bit closer as well, and roughed up my screen more. Gonna see what happens.