Algae Scrubber Basics

[MaccaPopEye]

Hi guys,

Sorry for the long post but I am getting ready to build my first ATS! This is a massive thread so I haven’t read all of it but I have read the basics and the updated basics (some awesome info in there). The ATS will be an LED waterfall in an enclosed box.

I have ordered the acrylic to build a box and the lights are also on their way. I was just hoping you guys could double check everything for me to make sure I am on the right track before it is built and too late.

(I did this in metric so I have roughly converted all of the below into inches)

Screen:
The light reflectors are 7" wide x 5.5" tall so that will be the size of the box. After I take away a bit of room for the slot pipe and a bit of space on the sides and bottom this leaves me with 6"x4" of grow space for a screen (24 square inches).

My tank is roughly 100gal and is currently lightly stocked but eventually it won’t be. Due to this I was going to start out with a 12 square inch screen (4"x3") and when I start feeding more than 1 cube a day replace it with a 24 square inch screen (6"x4"). Is this the right way to go since my tank could remain lightly stocked for quite a while or should I just start off with the 24 square inch screen? I currently only feed a little pinch of pellets twice a day and maybe once every week or so I throw in 1 cube of frozen food spaced out over two days.

I just don’t want to put in a 24 square inch screen and not have it mature properly.

Pump:
Initially the pump I will be using is a cheap 800GPH pump so it would be a bare minimum for the 24 square inch screen but I will be upgrading my return pump in a month or two so it will be more than big enough to T the scrubber off that so it will have over 800GPH. This is another reason to go with the 12 square inch screen to begin with.

Lights:
I don't like electrical DIY stuff so I have ordered 2 of the 20W versions of this:
http://www.ebay.com/itm/25124852971...49&var=550222621114&ssPageName=STRK:MEBIDX:IT

It is a 20W multichip made up of 1W LEDs so I'm assuming that it has about 10W of actual draw.

This is almost double the maximum for a 12 square inch screen (6W actual draw) and a bit less than the maximum for the 24 square inch screen (12W actual). Due to this I would use a bit of diffuser if I went with a 12 square inch screen to start and I am hoping it will be enough to upgrade to a 24 square inch screen.

And how far away from the screen should I place the lights?

I think I have covered everything. Thankyou heaps in advance for any pointers you can give me.

Cheers,

Macca

 

[sensei]

Scrubbers compared to refugiums
o Filtration with algae is proportional photosynthesis, which is proportional to Light X Air Water Turbulence Flow X Attachment. Meaning, stronger light grows more algae; stronger air/water interface turbulence grows more algae; and stronger attachment lets more algae grow without it detaching and floating away. A scrubber is thus designed to maximize Light, Flow, and Attachment.

Thanks Santa Monica,
If I understand correctly, it is the scrubber design that maximizes the potential of the algae to absorve nutrients because it provides the best conditions of light, flow and attachement for the algae to grow, and this is what makes the scrubber more potent than a fuge.

would a scrubber be capable of eliminating bryopsis in a tank?
regards

 

[Floyd R Turbo]

Capable, yes. Does that mean it will, not necessarily. Bryopsis is one of those very difficult things to eradicate. Different strains or variations are more aggressive and react differently to treatment techniques. That and bubble algae are the tough ones to combat, no matter what you have for filtration

 

[Spar]

i am having a tough time estimating how many cubes i will be feeding. with fish i knew, but i will be going no-fish for the next 6 to 12 months; coral and inverts only.

im not so worried about getting the size of the screen wrong, but more-so getting the lights right.

are there any general guidelines for getting this 'cube quantity' thing right?

 

[SantaMonica]

I've been thinking about adding a scrubber to my system to keep algae under control. i do water changes and run gfo but I have 3 tangs and feed a good amount. Do you think a scrubber is the way to go or should I go a different route? 180g tank with 40g sump, jns cones co3 skimmer

You are in the right place to ask

Your GFO is the only thing that is doing much nutrient removal, so yes a scrubber would help a lot.

I was going to start out with a 12 square inch screen (4"x3") and when I start feeding more than 1 cube a day replace it with a 24 square inch screen (6"x4"). Is this the right way to go since my tank could remain lightly stocked for quite a while or should I just start off with the 24 square inch screen?

Best to start with the bigger one, so that the algae is well attached.

800GPH pump so it would be a bare minimum for the 24 square inch

800 is more than enough. A 6" long screen only needs 6 x 35 = 210 gph.

And how far away from the screen should I place the lights?

2 or 3 inches.

If I understand correctly, it is the scrubber design that maximizes the potential of the algae to absorve nutrients because it provides the best conditions of light, flow and attachement for the algae to grow, and this is what makes the scrubber more potent than a fuge.

would a scrubber be capable of eliminating bryopsis in a tank?

Exactly. So the nutrients go to your scrubber instead, like a stronger vacuum. And you get more pods than previously thought, too. I see full grown amphipods all the time.

Yes a scrubber works on briopsys, but it is last to go because it has "roots" which pull nutrients out of the rock. After a while though, even the nutrients in the rock run out.

are there any general guidelines for getting this 'cube quantity' thing right?

Yes, by looking at the growth. Continued dark growth means your lights are not strong enough.

 

[Spar]

Is there a specific company that people tend to buy retrofit kits for the philips luxeon led's?

 

[Spar]

just to confirm my plan sounds OK here is what I have math wise:
1) 450g water volume (just FYI)

2) plan to feed 4 cubes per day (at least in early days of my fishless rebuild, feeding coral/inverts only at this point)

3) 4 cubes x 12 sq/in = 48 sq/in sheet, but I will multiple by 1.5 given my tank size, giving me a goal of ~64 sq/in sheet
is it better to go 8x8 sheet or 10x6.4 or other? Does it really make a difference at this size?
8x8 would need 280gph and 10x6.4 would need 350gph

4) LED's I will need 8 minimum (64 / 8) to 16 maximum (64 / 4) of 3W bulbs per side (16 to 32 total)
I will go with somewhere between 6 Deep Red, 1 Royal Blue and 1 Deep/Hyper Violet per side up to double that


Especially considering my tank size, does this all seem about right for a planned heavily stocked SPS/LPS tank? Fish load will increase at a very slow pace over a couple year period.

 

[SantaMonica]

Screen shape really does not matter too much, as long as most of the screen is in front of the light.

Go with double the LEDs, with 1/2 of them on a separate power supply.

Size is fine for now. Instead of bigger now, it's better to have add a second one later and clean them alternately.

 

[Spar]

Screen shape really does not matter too much, as long as most of the screen is in front of the light.

Go with double the LEDs, with 1/2 of them on a separate power supply.

Size is fine for now. Instead of bigger now, it's better to have add a second one later and clean them alternately.

i feel like i am being a little dense here, so bare with me

by "go with double the LEDs", do you mean to make it a light unit that is twice as long as needs to be (say 16 horizontal x 8 vertical)?, that way I can just later on add a second 8x8 sheet next to my current one and turn the next set of LED's on?

Assuming that is what you mean, per 1/2-section, what is the best quantity of LED's to get for each 8x8 section? 8, 12, or 16 per side? I assume it would be best to go with 16 and then I could just play with photoperiod and intensity to get things right?

 

[MaccaPopEye]

800 is more than enough. A 6" long screen only needs 6 x 35 = 210 gph.

Of course. I stupidly did 24" x 35 haha thankyou. I'll be upgrading my return anyway but wont be in such a rush.

I'll go with the bigger screen to start with as per your advice and I think I will go with the lights 2" away from the screen as thats pretty much what I was planning for anyway.

Thanks heaps for your advice. When I finally get around to building it I will post up pics :thumbsup:

 

[Spar]

Of course. I stupidly did 24" x 35 haha thankyou.

When I was doing the math yesterday I was doing the same thing and baffled that you would need something like 2000gph for a 6x6 screen! finally re-read and noticed that there was mention of it being linear, not square! Big relief, ha!

 

[MaccaPopEye]

When I was doing the math yesterday I was doing the same thing and baffled that you would need something like 2000gph for a 6x6 screen! finally re-read and noticed that there was mention of it being linear, not square! Big relief, ha!

And I'm sure we won't be the last to do it either :lolspin:

Can't wait for my lights to arrive so I can start building this scrubber :bounce2:

 

[Spar]

And I'm sure we won't be the last to do it either :lolspin:

Can't wait for my lights to arrive so I can start building this scrubber :bounce2:

Who did you order the lights from?

 

[Floyd R Turbo]

i feel like i am being a little dense here, so bare with me

by "go with double the LEDs", do you mean to make it a light unit that is twice as long as needs to be (say 16 horizontal x 8 vertical)?, that way I can just later on add a second 8x8 sheet next to my current one and turn the next set of LED's on?

Assuming that is what you mean, per 1/2-section, what is the best quantity of LED's to get for each 8x8 section? 8, 12, or 16 per side? I assume it would be best to go with 16 and then I could just play with photoperiod and intensity to get things right?

go to this post (referenced in my sig) regarding DIY LED spacing

http://www.reefcentral.com/forums/showthread.php?p=23906862#post23906862

4) LED's I will need 8 minimum (64 / 8) to 16 maximum (64 / 4) of 3W bulbs per side (16 to 32 total)
I will go with somewhere between 6 Deep Red, 1 Royal Blue and 1 Deep/Hyper Violet per side up to double that

Which I see that you read...but that minimum number IMO is the deep red only, don't count the RBs or the HV.

I think what SM was saying was go with 16 DRs per side, with half on one circuit and half on another so you could switch half on to start, half on later once you get a mature screen.

However my recommendation would be to wire them in 2 circuits just like if you were only going to run one at first, but then parallel them together so that they only run at 1/2 current. You will get better coverage and less chance of photosaturation by running 660s at 700mA on a bare screen. However, distance from the screen would decrease the chance of this. If you put the array at 3"-4" or further from the screen, you should be OK running at 700mA

 

[sensei]

Floyd,

I would like to know if people like you that have a well designed Algae scrubber for the amount of cubes feed in tank still use any other method to lower nitrates and phosphates in your tanks?

Or is the scrubber potent enough by itself to have the N and P levels in check without using any nitrate and phosphate reducing materials, such as pellets, NOPOX (from redsea) or vodka and carbon dosing ??

I would like to know it scrubber is used in conjuntion with all tese other methods or ussually not

2.- it was mentioned before that scrubber also grows pods, but when you clean the scrubber you through away the algae you would also discart all pods so there is not a constant harvest of pods??

please tell me your thoughts
Thanks

 

[Floyd R Turbo]

I have 2 tanks where I use nothing but a 4x6 screen (2 cube/day scrubber)

I don't test that often, but I did recently and on one (my personal sumpless 120 w/about 90g effective water volume) N=0.5-1.0 (Salifert) and P=0.06 (hanna). This was pretty typical until about a month ago - a month before that (2 months ago) I added about 14 more fish (Anthias and cardinals) and about doubled my feeding. Nitrates went up, so to phosphates. I had to re-configure the scrubber (which sits on top of the tank) so that it could drain better and take a higher flow. I also did a PWC (20g, or about 25%) just because I wanted to start changing the salt brand and well I hadn't done a PWC in a few years...

Other tank is a 144, and that water tested N=0 P=0.02.

For both tanks, all I do is top off and clean the scrubber every 10-14 days and very little else. For both tanks, this has been pretty much my only maintenance regimen for coming up on 4 years. Besides the inevitable scraping the glass and cleaning the pumps/power heads every now and then.

On my tank, I feed a decent square (probably 2 sq in) of either LRS or a DIY food every day, and clean the scrubber every 10. On the other tank, it's about half that on feeding, and cleaning every 14 days.

Regarding pods, you will have millions of microscopic baby copepods that come off the screen, so cleaning and throwing away is no big deal IMO. You don't need a planted fuge to grow pods, a bunch of LR in your sump will become a pod colony.

 

[sensei]

I have 2 tanks where I use nothing but a 4x6 screen (2 cube/day scrubber)

I don't test that often, but I did recently and on one (my personal sumpless 120 w/about 90g effective water volume) N=0.5-1.0 (Salifert) and P=0.06 (hanna). This was pretty typical until about a month ago - a month before that (2 months ago) I added about 14 more fish (Anthias and cardinals) and about doubled my feeding. Nitrates went up, so to phosphates. I had to re-configure the scrubber (which sits on top of the tank) so that it could drain better and take a higher flow. I also did a PWC (20g, or about 25%) just because I wanted to start changing the salt brand and well I hadn't done a PWC in a few years...

Other tank is a 144, and that water tested N=0 P=0.02.

For both tanks, all I do is top off and clean the scrubber every 10-14 days and very little else. For both tanks, this has been pretty much my only maintenance regimen for coming up on 4 years. Besides the inevitable scraping the glass and cleaning the pumps/power heads every now and then.

On my tank, I feed a decent square (probably 2 sq in) of either LRS or a DIY food every day, and clean the scrubber every 10. On the other tank, it's about half that on feeding, and cleaning every 14 days.

Regarding pods, you will have millions of microscopic baby copepods that come off the screen, so cleaning and throwing away is no big deal IMO. You don't need a planted fuge to grow pods, a bunch of LR in your sump will become a pod colony.

WOW, it sounds like a Disney story... I wish I can have such results in my tanks.

let me see it I understood correctly your abbreviation for PWC: you did NOT do any Periodic Water Change for years? sorry to ask again, but I did not think this was possible
Is it and only fish tank or mixed reef and fish?
so just the algae scrubber and skimmer?
I ask because I have read that some people do not use a skimmer?

waiting for your reply
thanks

 

[SantaMonica]

by "go with double the LEDs", do you mean to make it a light unit that is twice as long

No, I probably meant just make it twice as strong.

is the scrubber potent enough by itself to have the N and P levels in check without using any nitrate and phosphate reducing materials

Certainly. Hundreds of folks do this. This is how all the oceans, lakes and rivers are filtered.

it was mentioned before that scrubber also grows pods, but when you clean the scrubber you through away the algae you would also discart all pods so there is not a constant harvest of pods

Every minute there are pods falling out of the scrubber. The fish learn this and hang out downstream.

And my current reef pond tangs have also learned to eat only from the scrubbers, not caring much about nori. So I'm going to remove the scrubbers near the rock, so they will have to come out into the open to feed.

you did NOT do any Periodic Water Change for years? sorry to ask again, but I did not think this was possible

Certainly possible, and very common. Water changes only remove a small amount of nutrients and food particles that day; they don't do anything else. A scrubber is constantly removing nutrients, but leaving food particles in the water.

 

[karimwassef]

No, I probably meant just make it twice as strong.



Certainly. Hundreds of folks do this. This is how all the oceans, lakes and rivers are filtered.



Every minute there are pods falling out of the scrubber. The fish learn this and hang out downstream.

And my current reef pond tangs have also learned to eat only from the scrubbers, not caring much about nori. So I'm going to remove the scrubbers near the rock, so they will have to come out into the open to feed.



Certainly possible, and very common. Water changes only remove a small amount of nutrients and food particles that day; they don't do anything else. A scrubber is constantly removing nutrients, but leaving food particles in the water.

Is this an in-tank scrubber? Got pictures?

 

[Floyd R Turbo]

let me see it I understood correctly your abbreviation for PWC: you did NOT do any Periodic Water Change for years? sorry to ask again, but I did not think this was possible
Is it and only fish tank or mixed reef and fish?
so just the algae scrubber and skimmer?
I ask because I have read that some people do not use a skimmer

PWC = Partial Water Change

Mixed reef (my tank):



No skimmer, only an algae scrubber

There more than one way to structure filtration so that you don't have to do PWCs to keep nutrients in check. But that doesn't meant that you should. PWCs are still valuable for many other reasons.