Algae Scrubber Basics

[jwoyshnar]

I run both also, have good growth on both.

 

[salty joe]

How lond have you gyys been running both Chaeto and the sm style?

 

[saitoking]

Saitoking, just out of curiosity, how much light are you using. I think you and I are in a similar situation, but i'm about 1 month ahead of you. My ATS is on a 120 FOWLR, but my nitrates were in the 100 range before I began. My growth looked very similar to yours up until two or three weeks ago. At that point, I began seeing small clumps of the green stringy stuff.

A couple days ago I added two more 23 watt CFL bulbs, which brings my total to 6 - 23 watt CFL's on a 14" W x 10" screen.

I've tried to post some pictures, but they are always too huge for the site. What do you use to take your pictures with, I'll try to post a set up of what I have going on.

I am using 2x23 CFL at 9 hours a day and my screen is 6"x8". How many hours are you running?

 

[crn005]

You're right, one blue or two at half-power, which is what I do. I wire them into the (+) on the first blue, then I connect the (+) and (-) of the first to the second, then out of the (-) on the second blue, effectively making a current divider so that each blue runs at 1/2 power within a series string of reds. If your LEDs are not matched well then you might get a little more out of one LED, but from what I have been able to tell, there's really no problem doing it this way. I would not mix a blue and a violet this way though.

Regarding the graph, I've looked at many graphs and the peaks are all over the place. The one above makes it look like the B peak is at 655 and the A peak at 690, and on the other end it's A at 435ish and B at closer to 490. Seems far off what I have seen, don't know who to trust sometimes!!

But your discussion seems to make sense.

As far as the LEDs, Rapid seems to carry the lower spectrum, Steve's LED carries a "true violet" which peaks at 422.5nm and runs at 700mA, and I have a few, and will be testing these.

Oh I agree. Most charts don't seem to accurately graph what the specific peaks are. The thing to take away from this graph is the absorbtion spectrum doesn't take a big dive between the two chlorophyll spikes and that the photochemical effenciency rate increases the farther left on the spectrum you go. I found some other graphs that had the peaks charted differently but they all showed the same thing in regards to the absorbtion and efficiency. If you have to choose between only running the royal blues and violets, then it's pretty apparent to go with the royal blues. They do a good job covering both chlorophylls.

What's the benefit of running the two LEDs at half power?

 

[caribfan]

I am using 2x23 CFL at 9 hours a day and my screen is 6"x8". How many hours are you running?

I am running 18 hours / day, 3x23 CFL per side. Maybe this is too long of a photo period, I don't know.

 

[crn005]

I am running 18 hours / day, 3x23 CFL per side. Maybe this is too long of a photo period, I don't know.

Nope. 18 hours fits right on schedule with the rule for CFL lighting.

 

[saitoking]

From Floyds post
Lighting

There are 3 basic types of light sources that people use: CFL, T5HO, and LED.

Since LED Algae Scrubbers are becoming all the rave, I have further expanded the discussion regarding LEDs. The LED based Algae Scrubber has a different set of rules to follow with respect to wattage and photoperiod, as well as a few other factors. So to avoid confusion, I kept the LED section separate and it follows the fluorescent section.

In the cases of fluorescent lighting, the optimum spectrum / light temp for growing algae is 2700K-3500K, with 2700K-3000K getting the best results.

Proper wattage of light and proper flow to the screen are the critical factors; color temperature / spectrum comes in behind those. You can use higher K ratings, but the real-world (anecdotal) evidence suggests that the optimal range for growing algae is heavy in the red spectrum. If you look at regular plant grow lights, you will find that most of them (especially LED grow lights) are very heavy in red.

Power Compact, or PC lamps, are not recommended, because they run way too hot for the amount of light you get out of them. I don't even care for them for tank lighting.

Quantity of lighting is dependent on the size of the Algae Scrubber screen (dimensional area). In general, you want 1 watt (actual, NOT "œincandescent equivalent") of light per square inch for optimal scrubbing power. You can get away with less, but I would not recommend it. You will likely experience problems at some point.

As you will notice throughout this thread, it is generally stressed to follow the minimum 1 watt per square inch guideline. This is because it solves many Algae Scrubber issues. The reason behind this is scientific. Light interacts with algae and causes N and P (and ammonia & nitrite, among other things) to be absorbed, and chlorophyll is created (among other things). The more light, the more nutrient reduction you get. There is a direct correlation between the quantity of light supplied and the amount of nutrient reduction capability.

A non-vertical Algae Scrubber requires at minimum 1.5 times the light as you would need for a comparable vertical single sided Algae Scrubber. Here is where I will switch to the total surface area method. A vertical single sided 1-cube per day Algae Scrubber would be 24 square inches, lit with 12 watts, or 0.5 watts per square inch of total surface area. A non-vertical Algae Scrubber needs to be 2x as large, or 48 square inches, and have 18 watts of light, which results in 0.375 watts per square inch. I would argue that you need at least 0.5 watts/sq in, if not a full 1.0 watt per square inch to make up for the efficiency loss factor inherent to a non-vertical Algae Scrubber because of channeling and/or water draining through the screen instead of across the algae mat. Older dump-bucket or surge style Algae Scrubbers may not have this problem, but then again, you're only filtering when the water is moving fast, which is only periodically (again, boundary layer). I hope this convinces you not to try a non-vertical Algae Scrubber, unless you just think it would be cool.

In general, you need to run your lighting for 18 hours on, 6 hours off (see UPDATE below). All life needs downtime. Plants are no exception. They have adapted to the environment over millions of years, and as the saying goes, you can't fool Mother Nature. So don't go thinking that you can run lights 24/7 and get 25% more algae growth, it doesn't work that way. The lights should be run on the reverse cycle of your display tank lighting; this assists in maintaining pH at night, as well as spreads the light-induced heat load more evenly throughout the day.

You want the lights as close as possible, within reason. The effective power/intensity of light follows the inverse square law. If you move a light twice as far away, the intensity drops by a factor of 4. If you move it twice as close, you get 4x the intensity. The balance point seems to be about 4" from the screen for CFL, and about 2" with T5HO. The reason for 4" away for CFL stems from hot spot issues due to the concentrated signature of the lamp; CFLs need to be a bit further away to cover the proper area without too much intensity. T5HOs do not have this problem, as the light is very evenly spread.

As far as spacing is concerned, CFLs need to be spaced according to the allowance of the design. If you need 2 per side, just position them for the best coverage. This is really on a case-by-case basis.

The advent of the smaller, higher light screen (discussed in detail to follow) has presented an issue with respect to CFL Algae Scrubbers "“ how to fit all that light into an even smaller area! There is no rule saying that you cannot trim the CFL reflectors so that they can "˜cross over' each other. I literally just thought of this as I was editing this. Think of it like when you're watching a movie and someone is looking through binoculars "“ you see the "œ8"-on-it's-side shaped viewing area. Just trim both reflectors where they intersect using some tin snips or a wire cutter. (Be careful of sharp edges!) You may lose a little light from one lamp that is throw to the adjacent lamp (which it can now "œsee") but since we're concentrating the screen down in size, we need acceptable losses, and this is one. There are also socket splitters that you can use so that you can put 2 CFLs into one socket. However, you lose a little more with this method because the lamps will extend out from the reflector.

As for T5HO, you generally want a lamp spacing of 2-3". For T5HO, your Algae Scrubber will generally need to be designed around the lamps and spacing. CFLs are more flexible in this respect, allowing a variety of configurations.

If you run your lighting 18 on/6 off, the lamps must be replaced every 3 months. This is not just a rule for Algae Scrubbers, you will see many people make this suggestion for refugium lighting as well. That is because there is a power drop-off and a spectrum shift that takes place over time, and when you go much past 3 months, you hit that drop-off point. We can't see the difference, but then again, we're not algae - it can. The result is that your screen will slow down growing and reduce filtration, which you do not want.

The light source needs to be positioned so that it is pointing directly at the screen material. Do not place the fixture so that it points parallel to the screen (from the ends or the top), place it so that directs the light toward the screen. Perfectly perpendicular is optimal, but if you have to point it at somewhat of an angle just to make it work, that will be fine. This is more of a concern for CFL than linear sources (T5HO), however I have seen a few T5HO build with the lamp 4 inches above the screen, shining straight down. They didn't work so well.

 

[sail33]

lights

lights

I'm so glad someone posted this again. THANKS
my questions are answered.
I've been using CFLs with minimum results and plan to switch over to LEDs ASAP.

From Floyds post
Lighting

There are 3 basic types of light sources that people use: CFL, T5HO, and LED.

Since LED Algae Scrubbers are becoming all the rave, I have further expanded the discussion regarding LEDs. The LED based Algae Scrubber has a different set of rules to follow with respect to wattage and photoperiod, as well as a few other factors. So to avoid confusion, I kept the LED section separate and it follows the fluorescent section.

In the cases of fluorescent lighting, the optimum spectrum / light temp for growing algae is 2700K-3500K, with 2700K-3000K getting the best results.

Proper wattage of light and proper flow to the screen are the critical factors; color temperature / spectrum comes in behind those. You can use higher K ratings, but the real-world (anecdotal) evidence suggests that the optimal range for growing algae is heavy in the red spectrum. If you look at regular plant grow lights, you will find that most of them (especially LED grow lights) are very heavy in red.

Power Compact, or PC lamps, are not recommended, because they run way too hot for the amount of light you get out of them. I don't even care for them for tank lighting.

Quantity of lighting is dependent on the size of the Algae Scrubber screen (dimensional area). In general, you want 1 watt (actual, NOT "œincandescent equivalent") of light per square inch for optimal scrubbing power. You can get away with less, but I would not recommend it. You will likely experience problems at some point.

As you will notice throughout this thread, it is generally stressed to follow the minimum 1 watt per square inch guideline. This is because it solves many Algae Scrubber issues. The reason behind this is scientific. Light interacts with algae and causes N and P (and ammonia & nitrite, among other things) to be absorbed, and chlorophyll is created (among other things). The more light, the more nutrient reduction you get. There is a direct correlation between the quantity of light supplied and the amount of nutrient reduction capability.

A non-vertical Algae Scrubber requires at minimum 1.5 times the light as you would need for a comparable vertical single sided Algae Scrubber. Here is where I will switch to the total surface area method. A vertical single sided 1-cube per day Algae Scrubber would be 24 square inches, lit with 12 watts, or 0.5 watts per square inch of total surface area. A non-vertical Algae Scrubber needs to be 2x as large, or 48 square inches, and have 18 watts of light, which results in 0.375 watts per square inch. I would argue that you need at least 0.5 watts/sq in, if not a full 1.0 watt per square inch to make up for the efficiency loss factor inherent to a non-vertical Algae Scrubber because of channeling and/or water draining through the screen instead of across the algae mat. Older dump-bucket or surge style Algae Scrubbers may not have this problem, but then again, you're only filtering when the water is moving fast, which is only periodically (again, boundary layer). I hope this convinces you not to try a non-vertical Algae Scrubber, unless you just think it would be cool.

In general, you need to run your lighting for 18 hours on, 6 hours off (see UPDATE below). All life needs downtime. Plants are no exception. They have adapted to the environment over millions of years, and as the saying goes, you can't fool Mother Nature. So don't go thinking that you can run lights 24/7 and get 25% more algae growth, it doesn't work that way. The lights should be run on the reverse cycle of your display tank lighting; this assists in maintaining pH at night, as well as spreads the light-induced heat load more evenly throughout the day.

You want the lights as close as possible, within reason. The effective power/intensity of light follows the inverse square law. If you move a light twice as far away, the intensity drops by a factor of 4. If you move it twice as close, you get 4x the intensity. The balance point seems to be about 4" from the screen for CFL, and about 2" with T5HO. The reason for 4" away for CFL stems from hot spot issues due to the concentrated signature of the lamp; CFLs need to be a bit further away to cover the proper area without too much intensity. T5HOs do not have this problem, as the light is very evenly spread.

As far as spacing is concerned, CFLs need to be spaced according to the allowance of the design. If you need 2 per side, just position them for the best coverage. This is really on a case-by-case basis.

The advent of the smaller, higher light screen (discussed in detail to follow) has presented an issue with respect to CFL Algae Scrubbers "“ how to fit all that light into an even smaller area! There is no rule saying that you cannot trim the CFL reflectors so that they can "˜cross over' each other. I literally just thought of this as I was editing this. Think of it like when you're watching a movie and someone is looking through binoculars "“ you see the "œ8"-on-it's-side shaped viewing area. Just trim both reflectors where they intersect using some tin snips or a wire cutter. (Be careful of sharp edges!) You may lose a little light from one lamp that is throw to the adjacent lamp (which it can now "œsee") but since we're concentrating the screen down in size, we need acceptable losses, and this is one. There are also socket splitters that you can use so that you can put 2 CFLs into one socket. However, you lose a little more with this method because the lamps will extend out from the reflector.

As for T5HO, you generally want a lamp spacing of 2-3". For T5HO, your Algae Scrubber will generally need to be designed around the lamps and spacing. CFLs are more flexible in this respect, allowing a variety of configurations.

If you run your lighting 18 on/6 off, the lamps must be replaced every 3 months. This is not just a rule for Algae Scrubbers, you will see many people make this suggestion for refugium lighting as well. That is because there is a power drop-off and a spectrum shift that takes place over time, and when you go much past 3 months, you hit that drop-off point. We can't see the difference, but then again, we're not algae - it can. The result is that your screen will slow down growing and reduce filtration, which you do not want.

The light source needs to be positioned so that it is pointing directly at the screen material. Do not place the fixture so that it points parallel to the screen (from the ends or the top), place it so that directs the light toward the screen. Perfectly perpendicular is optimal, but if you have to point it at somewhat of an angle just to make it work, that will be fine. This is more of a concern for CFL than linear sources (T5HO), however I have seen a few T5HO build with the lamp 4 inches above the screen, shining straight down. They didn't work so well.

 

[Eurobeaner]

Mines been running awhile. Doing really well. Was my only filtration until I added a small skimmer(very undersized) last week. It seems that the scrubber has actually been growing more since. Only time will tell.

I typically remove most the water from the mat before I go to the sink. Makes it much better and less messy to remove the growth.

7 days growth.

Not cleaned on left, cleaned on right.

 

[Eurobeaner]

Double

 

[Skinnysloth]

Really interesting setup Eurobeaner. It that a surge type ats?

 

[Eurobeaner]

More of a dump tray. Instead of being counter weighted, it's double sided. So when one side fills up, it dumps which switches the water to the other side.

Vid of setup when everything was fresh. A lot of tweaks since then (quiet it down, and even out the weights of each side) , but you can see the normal operation.

http://i1081.photobucket.com/albums...-B1CA-978C5349B87A-17015-00001721CC730C2A.mp4

 

[nanomania]

kool idea.......

 

[nanomania]

the dump bucket thing is actually the natural wave format, that comes in and goes back.... the only down side is the sound...

 

[nanomania]

Here are the screens that i bought... need advise... As im from india, the canvas screen here is really thin and not thick enough to make it rough... so i bought 2 more... here are the pics:

 

[nanomania]

The last screen in the pic is really firm and better of the 2 above... do i really need to scrub it or its ok? please suggest which to use..

 

[Eurobeaner]

the dump bucket thing is actually the natural wave format, that comes in and goes back.... the only down side is the sound...

But... There are ways to make it get very quiet. I've made a couple changes to mine, and if I just built another one I could get it completely silent I think.

 

[nanomania]

please help with the screen selection...

 

[Floyd R Turbo]

The white stuff is the closest to what I use - looks like knitting canvas, 7 holes per inch, I know that you can get that in a "clear" which is not really clear, just more of a milky translucent white, and you can get it in colors, one of which is opaque white - which it looks like you have there.

The fine black stuff looks like window screen material. Don't use it. Can't rough it up, and it's not rough enough.

The thicker slant-crossed black stuff looks pretty good. I would use that or the white stuff, but it all depends on how well it roughs up.

I hear a lot from people overseas that they have a hard time finding the knitting canvas that we over here use. From what I have seen over the years, it is the perfect material. It's almost like someone needs to setup a network of people in other countries to ship a bunch of this stuff to so that they can distribute it!!!

 

[nanomania]

The white stuff is the closest to what I use - looks like knitting canvas, 7 holes per inch, I know that you can get that in a "clear" which is not really clear, just more of a milky translucent white, and you can get it in colors, one of which is opaque white - which it looks like you have there.

The fine black stuff looks like window screen material. Don't use it. Can't rough it up, and it's not rough enough.

The thicker slant-crossed black stuff looks pretty good. I would use that or the white stuff, but it all depends on how well it roughs up.

I hear a lot from people overseas that they have a hard time finding the knitting canvas that we over here use. From what I have seen over the years, it is the perfect material. It's almost like someone needs to setup a network of people in other countries to ship a bunch of this stuff to so that they can distribute it!!!

The white canvas is used for knitting, but its really thin so if a rough it up, it might tear... the black thick is nice thick and can be roughed up.. i use it for my trutle to crawl out of water for basking... is it something about the size of hole?