Algae Scrubber Basics

[Floyd R Turbo]

Look over summary post 1035/1036...

 

[Travis1787]

u my friend are awesome .... cant wait to get this rollin lol

 

[srusso]

Well I finally got my ATS up and running for the most part. I had to order some special fittings to complete the build the way I wanted it. The PVC tee's that were at the bottom of the scrubber are now replaced with 4 way tee's so that way when I detach the scrubber from up top the upright supports don't just fall over.

It was a little tricky getting it to fit into the sump with how tall it is but since the bottom half of it is just dry fitted I just slipped it apart and reassembled in the sump.

Pictures.

I cant help but notice, that buying a supply of replacement zip ties would make your life so much easier. Each week cut the ties, clean the screen and re-attach screen using new zip ties. IMHO removing union fittings every week, bringing it all over to the sink, will suck and be awkward to clean.

Additionally over time the union fittings will wear and may start to leak... As well as the action of scrapping the screen putting tension at the point were the screen and the zip ties meet, may over time tear your screen...

Two union fitting are about $10, you could get a 500 count of zip ties for that... that would last you 250 cleanings or 250 weeks or 4.8 years... I bet by that time you wouldn't mind buying some more zip ties...

Dont take this as me ragging on you. The point I am trying to make here is that we all are building a filter system... all the little details need to be thought out for you to feel like its working well for you...

Just a thought... it wouldn't be hard for you to start doing it that way anyway and just leave the unions as is...

 

[Floyd R Turbo]

I always remove the screen from the slot and scrub the section that is in the slot very well so make sure it's clear. What I do is trim the excess of the zip tie off and then stick the tip of a razor blade in release the tab on the zip tie. I think in 6 months I've gone through maybe 12 or 16 zip ties.

You can also buy releasable zip ties, but I can only find them in lots of 50. They're very nice though.

 

[chrissu]

Here is a great link to the Smithsonian's own Dr. Adey regarding algal ecology. There is a lot of great scientific information about algal ecology from it's use in aquariums all the way up to industrial scale use

In the early 1980s, Walter Adey invented Algal Turf Scrubbing (ATS), a solar-algal process for removing nutrients, heavy meals, and toxic organics from water, and CO2 from the atmosphere. A large-scale capturer of solar energy, ATS produces an algal biomass that can be used as animal feed, fertilizer source, cellulosic and protein product, and energy source.

http://walteradey.com.

Note the link to http://www.algalturfscrubber.com/ Happy reading!

 

[chrissu]

1. No problem using skimmer and ATS, I believe the ATS will pull out the things that the skimmer misses.

2. ATS will out compete refugium. The micro algae will outcompete cheto and gradually starve it out of exhistance. If you wanted to make a softy and sponge refuge, then I'd say go for it.

3. Carbon dosing uses denitrifying bacteria and requires a very powerful skimmer to reduce NO2 by physically removing the bacteria that use the NO2. I believe a decrease in NO2 may choke out the ATS and make it less effective or obsolete. But the problem with Carbon dosing is the measuring, the constant fiddling with the levels, and the threat of a crash due to a biomass bloom. These risks don't exhist with an ATS working properly.

HTH
Aaron

+1 for dogstar's comments.

 

[bucks448]

I know it's been said that the ID of the slot pipe isn't that critical and to just match the plumbing you have, but I have to think that in some cases it does matter.

For example: I run my scrubber off my overflow at a full siphon. The bulkhead for the overflow is 1" ID, the plumbing is 1.25", so at most my overflow is 1". It splits at the sump and there's a valve to the .75" slot pipe and another valve to the end that just dumps into the sump. The valve to the .75" slot pipe is wide open, and the other valve is adjusted to keep a full siphon. So, at most, through the .75" slot pipe is 660gph based on this chart http://flexpvc.com/WaterFlowBasedOnPipeSize.shtml. This is almost right at the 35gph per horizontal inch needed for the 19" slot I have. If all this is correct, my current setup flow rate vs. size fell into place by accident.

However (and this is why I'm asking), I'm looking at re-doing my scrubber, going with an enclosed box, and T5s, but I'll be continuing to use the overflow as the supply. In the process I'll be making it longer because it's a little undersized now. So, in order to get the correct GPH per horizontal inch needed, for, say a 22" long scrubber, doesn't the slot pipe need to be 1" based on the chart linked above? A .75" slot pipe just can't flow enough with gravity, right?

I'm trying to make sure I get everything correct, on purpose this time

 

[bk_market]

I am in the process of building the algea scrubber. I have a 45g tank so im building a 7"x7" screen. Is it okay to extend the screen to 7"x9" because I need 2 extra inch for the screen to touch the water to eliminate dripping water sound. Should i leave the bottom 2" smooth or should I just rough it up anyway. Maybe more is better.

Another option would be making the screen 6"x9" which will give me a total of 54. Also im planning to use my maxijet 1200 which give me 295gph without any loss but I assume it will be ~230gph because the pump just right under the screen inside the sump which equal to 38gph.

Also I was trying to look for information regarding the screen. Is it the display tank water volume plus the sump water volume or just display tank? My sump hold about 20gal of water so counting it or not for me will make a big different.

 

[Floyd R Turbo]

I know it's been said that the ID of the slot pipe isn't that critical and to just match the plumbing you have, but I have to think that in some cases it does matter.

For example: I run my scrubber off my overflow at a full siphon. The bulkhead for the overflow is 1" ID, the plumbing is 1.25", so at most my overflow is 1". It splits at the sump and there's a valve to the .75" slot pipe and another valve to the end that just dumps into the sump. The valve to the .75" slot pipe is wide open, and the other valve is adjusted to keep a full siphon. So, at most, through the .75" slot pipe is 660gph based on this chart http://flexpvc.com/WaterFlowBasedOnPipeSize.shtml. This is almost right at the 35gph per horizontal inch needed for the 19" slot I have. If all this is correct, my current setup flow rate vs. size fell into place by accident.

However (and this is why I'm asking), I'm looking at re-doing my scrubber, going with an enclosed box, and T5s, but I'll be continuing to use the overflow as the supply. In the process I'll be making it longer because it's a little undersized now. So, in order to get the correct GPH per horizontal inch needed, for, say a 22" long scrubber, doesn't the slot pipe need to be 1" based on the chart linked above? A .75" slot pipe just can't flow enough with gravity, right?

I'm trying to make sure I get everything correct, on purpose this time

I don't really have much faith in charts. Especially when you're dealing with a full siphon overflow. Beananimal's chart is more applicable here, because it allows you to enter the vertical height of your drop which will affect your flow rate. Also having a tee and 2 shutoffs will affect the numbers. i am a big fan of testing actual flow. In your case it might be kind of tough, but I bet I could come up with a way.

But in general, the maximum flow will increase with the ID size, so I would up it to 1".

I am in the process of building the algea scrubber. I have a 45g tank so im building a 7"x7" screen. Is it okay to extend the screen to 7"x9" because I need 2 extra inch for the screen to touch the water to eliminate dripping water sound. Should i leave the bottom 2" smooth or should I just rough it up anyway. Maybe more is better.

Another option would be making the screen 6"x9" which will give me a total of 54. Also im planning to use my maxijet 1200 which give me 295gph without any loss but I assume it will be ~230gph because the pump just right under the screen inside the sump which equal to 38gph.

Also I was trying to look for information regarding the screen. Is it the display tank water volume plus the sump water volume or just display tank? My sump hold about 20gal of water so counting it or not for me will make a big different.

Tank size only, and do not subtract out displaced water. So if you run a 90 with a 1/2 full 40 sump, you just use 90. Oversizing the screen is fine. The effective scrubbing power is determined by the lighting mainly. So if you have a screen for a 45 that is 60 square inches and has 45 watts of light, it's still a 45g screen not 60.

 

[bk_market]

Ouch I picked up 2x CF bulbs 23w each so the total is 46wat Thought I do use the 8.5" diameter reflector so maybe that help out.

Is it 1wat per 1 square inch or that just the minimum. I was at home depot and I think the next bulb is 30wat or so. If I grab that then my total light would be 60w running on a 45 screen.

 

[Floyd R Turbo]

No you're fine, 46W total, one 23W on each side is perfect

 

[srusso]

I am in the process of building the algea scrubber. I have a 45g tank so im building a 7"x7" screen. Is it okay to extend the screen to 7"x9" because I need 2 extra inch for the screen to touch the water to eliminate dripping water sound. Should i leave the bottom 2" smooth or should I just rough it up anyway. Maybe more is better.

Another option would be making the screen 6"x9" which will give me a total of 54. Also im planning to use my maxijet 1200 which give me 295gph without any loss but I assume it will be ~230gph because the pump just right under the screen inside the sump which equal to 38gph.

Also I was trying to look for information regarding the screen. Is it the display tank water volume plus the sump water volume or just display tank? My sump hold about 20gal of water so counting it or not for me will make a big different.

Rough up the extra two inches and yes you should make it a little longer so it reaches the water line.

A maxijet more then likely will be a little underpowered for the job... You can try but I think you will come out short on screen coverage. If you already have the maxijet give it a try... If you about to buy a pump, go bigger.

Only build a scrubber sized for the display tank.

 

[srusso]

..The effective scrubbing power is determined by the lighting mainly...

This is true, however I don't want to give people the wrong idea. So it should be said scrubbers fail to work properly if the 3 basics are not balanced.

In order of importance:

Lighting
Flow
Rough Screen Area

If any one of these three are built improperly the effectiveness of the scrubber drops with respect to how far out of balance it is...

 

[ecomdesign]

I was calculating my screen size based on total water volume! Maybe I'm overdoing it then if I only need to build it to the size of the display tank... I have a 80 gal display with a 40 gal breeder sump. Half of my sump is loaded with more live rock.

With that in mind, my screen only has to be 8x10" which at 35gal/" of screen gives me 280gph, so I'm good with my current pump!!!



Taking into account the 1 watt per gallon of lighting rule, I also need 80 watts of light. T5HO will not work for such a small screen so CFL will have to be the lighting of choice. If I use the 23watt bulbs, I'll need 3 or 4 of them. I'm not sure how I will fit that many lights close to my screen. Won't it be a little tight for space?

 

[BluScrnOdeth]

I was calculating my screen size based on total water volume! Maybe I'm overdoing it then if I only need to build it to the size of the display tank... I have a 80 gal display with a 40 gal breeder sump. Half of my sump is loaded with more live rock.

With that in mind, my screen only has to be 8x10" which at 35gal/" of screen gives me 280gph, so I'm good with my current pump!!!



Taking into account the 1 watt per gallon of lighting rule, I also need 80 watts of light. T5HO will not work for such a small screen so CFL will have to be the lighting of choice. If I use the 23watt bulbs, I'll need 3 or 4 of them. I'm not sure how I will fit that many lights close to my screen. Won't it be a little tight for space?

Calculating your screen based on total water volume isnt a bad idea. You just need to cover it with light. Using the DT tank size is the minimum you should build the screen. I always make mine larger because i like a lot of fish in my tank. So the more fish you have, the bigger the screen has to be. I think a lot of people forget that the screen size is also dependant on the bioload in the tank. My tank is 350 gallons roughly including the refige and i made my screen big enough to handle ~380 gallons. I'll post some pics of how mine looks in a sec. I just build my tank so the screen is regrowing at this time. I just finished it about 2 weeks ago. My screen (dang i cant remember exactly off hand the size) but i think its 20" wide by 11" tall, i have 4 23w CFL's placed 4-6" away from the screen, it's recovering like crazy right now. Its also getting just under 35gph flow also.

I'll get some exact measurements later today.

 

[srusso]

I was calculating my screen size based on total water volume! Maybe I'm overdoing it then if I only need to build it to the size of the display tank... I have a 80 gal display with a 40 gal breeder sump. Half of my sump is loaded with more live rock.

With that in mind, my screen only has to be 8x10" which at 35gal/" of screen gives me 280gph, so I'm good with my current pump!!!

Thanks!

You cant really over do it... my scrubber is over sized by twice the tank volume... do I need it that way? No... just how I did it. On a side note, building an oversized scrubber means you need more water flow, light etc...
Because of that fact, its better to build a properly sized scrubber that has the right amount of light and flow, then an oversized scrubber that is starved of one or the other. I learned this first hand with my scrubber. Still don't have the flow quite right. So building an proper oversized scrubber maybe harder to than its worth.

 

[BluScrnOdeth]

drain to scrubber
<IMG src="http://www.aquatic-refuge.com/RandomPics/at1.jpg" width="600">

cheato in refuge. Started as a couple ounces, now i can fill a 5gal bucket easily
<IMG src="http://www.aquatic-refuge.com/RandomPics/at2.jpg" width="600">

slit all the way to the end
<IMG src="http://www.aquatic-refuge.com/RandomPics/at3.jpg" width="600">

<IMG src="http://www.aquatic-refuge.com/RandomPics/at4.jpg" width="600">

<IMG src="http://www.aquatic-refuge.com/RandomPics/at5.jpg" width="600">

i put a couple layers of ducktape, you cant see it in the pic, to firmly hold the end cap on
<IMG src="http://www.aquatic-refuge.com/RandomPics/at6.jpg" width="600">

coupler is NOT glued on for easy removal and positioning
<IMG src="http://www.aquatic-refuge.com/RandomPics/at7.jpg" width="600">

here you can see the flow it's getting
<IMG src="http://www.aquatic-refuge.com/RandomPics/at8.jpg" width="600">

had to build the case around it for the time being. it was splashing a lot as since i built the new tank and stand, it it a few inches taller so either tonight or tomorrow i'll be getting another screen to make it touch the water
<IMG src="http://www.aquatic-refuge.com/RandomPics/at9.jpg" width="600">


here is a video of my new tank with the scrubber in action
http://www.youtube.com/watch?v=TP4-fZ1DauQ

 

[BluScrnOdeth]

You cant really over do it... my scrubber is over sized by twice the tank volume... do I need it that way? No... just how I did it. On a side note, building an oversized scrubber means you need more water flow, light etc...
Because of that fact, its better to build a properly sized scrubber that has the right amount of light and flow, then an oversized scrubber that is starved of one or the other. I learned this first hand with my scrubber. Still don't have the flow quite right. So building an proper oversized scrubber maybe harder to than its worth.

building it oversized doesnt mean you have to make it wider, you can have it taller (if you have the room) and still use the same GPH you were before, just need more light.

But i WOULD recommnd making it bigger than "needed". You have to plan ahead for bioload. Underselling yourself will bite you in the end and your tank will let you know.

 

[bucks448]

I don't really have much faith in charts. Especially when you're dealing with a full siphon overflow. Beananimal's chart is more applicable here, because it allows you to enter the vertical height of your drop which will affect your flow rate. Also having a tee and 2 shutoffs will affect the numbers. i am a big fan of testing actual flow. In your case it might be kind of tough, but I bet I could come up with a way.

But in general, the maximum flow will increase with the ID size, so I would up it to 1".

Thanks Floyd. I'll go with a 1" slot tube in the new design. As for testing actual flow, I should be able to once I have a closed box scrubber. As it is, I'd have to devise a way to catch all the water cascading off the open bottom of the screen, and I have no room to work with (part of the reason for the redesign). If I tested with out the slot tube, the .75" pipe would more than handle all the overflow, at least according to Beananimal's calculator.

 

[bucks448]

Taking into account the 1 watt per gallon of lighting rule, I also need 80 watts of light. T5HO will not work for such a small screen so CFL will have to be the lighting of choice. If I use the 23watt bulbs, I'll need 3 or 4 of them. I'm not sure how I will fit that many lights close to my screen. Won't it be a little tight for space?

If you go with a wide reflector, like an 8.5" clamp-on light, you could go with one on each side and use a 42w CFL bulb. Then you're all set.