Algae Scrubber Basics

[Floyd R Turbo]

Originally Posted by karimwassef

Hmmm. So these 3D ATS seem to be working out, huh?

Is it basically an updraft but without bubbles?

Originally Posted by jason2459

I think it just refers to lights on both sides of the screen.

3D refers to the growth, not the method (waterfall vs upflow vs horizontal).

Originally Posted by karimwassef

It's not oxygen, it's the air interface that I believed reduces the ability of bacteria to take hold and gives an unfair advantage to the algae.

Originally Posted by jason2459

If there's research on that I would love to read it. Seriously, not being sarcastic.

I don't see how bacteria thatis aerobic wouldnt love the same environment.

Actually some have suggested that the algae forms a dynamic "substrate" that bacteria can populate, and then when you harvest the algae, you are also harvesting bacteria. Not sure how much this has been researched but it does make sense.

Maybe we're talking about different kinds of bacteria here though....

[jason2459]

Originally Posted by SantaMonica

Yes and you get it with a waterfall, or with upflowing bubbles. Technically, bubbles reduce the interface distance to zero for an instant.



I think it's CO2 that you mean. Oxygen does no good for algae growth.



Yes but the growth rate is less without the air/water interface. The air/water interface removes the boundary layer that stops nutrient transfer.



Dynamic Aquaria, by Adey.

Also www.ReefBase.org

I don't buy the air bubble spliting thing but thats just my opinion.

No O. Last I knew there's O in CO2 as well.

Will keep researching as alway. Thanks.

[jason2459]

Originally Posted by Floyd R Turbo

3D refers to the growth, not the method (waterfall vs upflow vs horizontal).


Actually some have suggested that the algae forms a dynamic "substrate" that bacteria can populate, and then when you harvest the algae, you are also harvesting bacteria. Not sure how much this has been researched but it does make sense.

Maybe we're talking about different kinds of bacteria here though....

Ah yes, I've seen HOG and Surf referring to 3d growth to I think.


I don't see why or what would stop bacteria of some type from growing on the screen with the algae or on the algae. I see all kinds of stuff growing with the algae.

One of several times I've sampled the ATS.
Search For Dinoflagellates in some Green Hair Algae: http://www.youtube.com/playlist?list...yCmtvWcQA1TZQy

[Floyd R Turbo]

Originally Posted by jason2459

No O. Last I knew there's O in CO2 as well.

"air" is overall always appropriate...

[jason2459]

Originally Posted by Floyd R Turbo

"air" is overall always appropriate...

Yes but not near as snarky

[karimwassef]

so what I'm hearing is that violent agitation of the algae is the target. Air is just a tool to that end.

[jason2459]

Not even sure violent is key? But flow certainly.

[SantaMonica]

BRS is a sponsor so hope it's ok to post their scrubber growth...

[DamonG]

I believe this about a week and a half after muy first cleaning.. Lol, I really need to stop taking cell pictures, and take my camera downstairs sometimes..

Sent from my SM-N910V using Tapatalk

[zachtos]

Is there a consensus yet on LED density?

I am plumbing my 300G right now, and have a 24" x 14" screen setup prepared, planning to light with deep red and 410nm UV LED (8:1 or so ratio). I am unsure if I need optics, or what is ideal to not burn them, obviously less waste light the better.

[Floyd R Turbo]

Originally Posted by zachtos

Is there a consensus yet on LED density?

I am plumbing my 300G right now, and have a 24" x 14" screen setup prepared, planning to light with deep red and 410nm UV LED (8:1 or so ratio). I am unsure if I need optics, or what is ideal to not burn them, obviously less waste light the better.

http://algaescrubber.zohosites.com/lighting-led.html

Deep Reds 2" on center, being able to dim them is a huge +. No lenses, you want light spread out & even not focused (leads to burning).

I don't know if UV is what you meant, but 410 is likely to be classified as "deep violet" not invisible Ultra Violet. 415-425 is what I recommend (hyper violet SemiLED are very good quality, other brands of violets might delaminate, they are prone to that)

for a 24 x 14 screen that is a ton of LEDs and is also really super huge, that's 336 sq in, did you size that according to volume or feeding? because that is a 28 cube/day screen...

[zachtos]

Originally Posted by Floyd R Turbo

http://algaescrubber.zohosites.com/lighting-led.html

Deep Reds 2" on center, being able to dim them is a huge +. No lenses, you want light spread out & even not focused (leads to burning).

I don't know if UV is what you meant, but 410 is likely to be classified as "deep violet" not invisible Ultra Violet. 415-425 is what I recommend (hyper violet SemiLED are very good quality, other brands of violets might delaminate, they are prone to that)

for a 24 x 14 screen that is a ton of LEDs and is also really super huge, that's 336 sq in, did you size that according to volume or feeding? because that is a 28 cube/day screen...

Is there a negative to oversizing really?

I also thought about optics and moving to 10-12" back from scrubber on both sides to use less LED and smaller heatsink/fixture.

"use one 3W LED on each side for every 12 square inches." Is this still true? because that puts me at 28 LED where you said every 2 inches center to center, that works out to 60 LED, or a 100% change of intensity based on my interpretation.

It will eventually be a heavily stocked SPS w/ tons of fish in the 300G. I calculated maybe 10-20 cubes but varies based on age of fish. I have a big skimmer, but hoped one day could run it part time only if the ATS works that well.

[Floyd R Turbo]

There can be if it is vastly oversized, but that is relative also. Meaning if you put a 10 cube/day scrubber on a tank fed 3/day, could be issues with growth trying to spread out across the whole screen and not growing green. Condensing down to match what you feed is generally better, or not much over 2x feeding.

For your example, making a 25+ cube/day scrubber when you are feeding 10-20, probably will be ok but there's not much "data" out there for large tank scrubbers that are overbuilt, so I guess it's hard to say if that "multiplier guideline" holds true as you scale up or if it has more to do with how much you oversize strictly based on "extra cubes" if you get what I mean.

Either way, if you oversize too much then you can end up with some problems but whether or not that happens depends on some factors that are more specifically related to your setup, and it's hard to predict.

Then there is the issue of flow and lighting, both of which increase with size, and cost you initial $ and also heat and monthly $.

You can always start with a conservative size and make it bigger if that ends up being the road you decide to go down.

[zachtos]

Originally Posted by Floyd R Turbo

There can be if it is vastly oversized, but that is relative also. Meaning if you put a 10 cube/day scrubber on a tank fed 3/day, could be issues with growth trying to spread out across the whole screen and not growing green. Condensing down to match what you feed is generally better, or not much over 2x feeding.

For your example, making a 25+ cube/day scrubber when you are feeding 10-20, probably will be ok but there's not much "data" out there for large tank scrubbers that are overbuilt, so I guess it's hard to say if that "multiplier guideline" holds true as you scale up or if it has more to do with how much you oversize strictly based on "extra cubes" if you get what I mean.

Either way, if you oversize too much then you can end up with some problems but whether or not that happens depends on some factors that are more specifically related to your setup, and it's hard to predict.

Then there is the issue of flow and lighting, both of which increase with size, and cost you initial $ and also heat and monthly $.

You can always start with a conservative size and make it bigger if that ends up being the road you decide to go down.

I suppose I can try to find a way to expand the design, but reserve the space during my build phase. Fish will be all juvenile, so the demand will kick up dramatically in coming years.

What about the calculations for LED / sq. inch or using optics and moving further back so I can have a smaller fixture?

[Floyd R Turbo]

You might find that the smaller scrubber works for quite a while, vs a temporarily oversized scrubber which has a higher potential to have issues

As for the fixture question, in theory that should work but if you move the fixture back away then add lenses to focus the light, you end up with the same # of LEDs. Now I'll say this, that spacing guide works well when you start out at 1/2 current/power and sometimes you can leave it there, but if you want to amp up the growth you can run them stronger if you have to load to support it. So it's #1 coverage and #2 power. If you use 1/2 the LEDs and full power with lenses from further away, that's the equivalent to 50% up close. Then you're power limited on what the light output can be, but then you can add LEDs if you find that you need them - so that's another way to offset the initial cost I guess.

[zachtos]

So is it 2 inches on center to every LED or 1 per 12 in sq? Every 2 inches works to 1 per 6 sq inches which is double.

[Floyd R Turbo]

physical spacing - a grid of LEDs in a 2" x 2" pattern, it's described on that link.

Minimum coverage: One LED on each side of every 8 sq in of screen
Maximum coverage: One LED on each side of every 4 sq in of screen

It's really the maximum coverage that is 2" O.C. = each LED covers a 2" x 2" area, another way of putting it (sorry)

24 x 14 = 336

336 /8 = 42 LEDs per side
336 /4 = 84 LEDs per side

[karimwassef]

I prefer to use PAR as a measure. I've been successful with ~200 PAR at the screen center. 300 is better, but 200 will do.

[zachtos]

Originally Posted by karimwassef

I prefer to use PAR as a measure. I've been successful with ~200 PAR at the screen center. 300 is better, but 200 will do.

Good to know, I have an apogee PAR meter, and have built LED fixtures twice now. 84 LED for a 12x24 area seems extreme, that's more than double I would need for a 24*24 area in an Sps tank.

[Fish'InMN]

Originally Posted by karimwassef

I prefer to use PAR as a measure. I've been successful with ~200 PAR at the screen center. 300 is better, but 200 will do.

Everyone should take this to heart - light intensity/output measurements are way more useful than LED number and power guidelines when it comes to recommending setups. This is the first PAR number I've seen in hundreds of pages on this topic and that is an insult to everyone involved.

[Floyd R Turbo]

Sorry I disagree that it's an insult to suggest a coverage configuration based on experience.

I understand that PAR can be useful but the issue as it's been explained to me is that 660nm Deep Red from LEDs does not always register properly on a PAR meter because of the nature of either the source or the bandwidth. I'm no PAR expert so don't take this as slamming on PAR. This is what I've been told by people who know LEDs better than I do...but now that they are making PAR meters that are more in-tune with LEDs (apogee) this may have changed.

Worst case: PAR can allow you to evaluate the evenness of coverage, but it won't accurately tell you what your intensity really is. What I mean by that is that let's say that your PAR reading is not accurately reflective of actual intensity due to said potential issue, so it's "off" by a factor of some kind. That factor will be common across the entire illumination area, so it can be effectively "cancelled out" because the variations in readings will all be relative to each other and therefore pertinent from the perspective of relative intensity. But that does not necessarily imply that the absolute intensity is correct.

What I know, based on a lot of experience, is that you can achieve even coverage by using a DIY array of LEDs of 660nm chips that are spaced out at around 2"-3" on center place about 1.5" +/- 0.5" from the screen.

If you can either 1) dim them or 2) diffuse them, this can help to avoid initial over-lighting (photosaturation).

It has been suggested way back somewhere in this thread that there should be a "Rule of PAR" (srusso suggested this as an idea) where your PAR of your scrubber should be matched to the PAR of your tank but this was dropped as feeding was the more relevant relationship, not tank lighting...but it might come into play in certain situations, so I wouldn't say that I have ruled it out completely.

[Floyd R Turbo]

For instance here is an intensity reading that someone sent me, this is an array of DRs at 2" on center with HVs in the center of each "square" of reds, with the HV at 50% relative to the DRs and the entire array dimmed to "50%" and then at full intensity



I'm not sure how this translates to PAR but what he told me was that this was measured at dead center in front of the fixture, and there was little to no difference at any other point in front of the fixture or at the end even. So I know that the coverage technique works - because hotspots cause major issues, and it doesn't take much to create a hotspot.

I found out early on with LEDs that this is the case. Take an array for a 4x6 screen that is 6 deep reds in a 2x4 rectangle pattern and then put a royal blue right in the middle of that rectangle, and put one such array on each side of the screen. The result is you will see a bare spot dead center on the screen about 1.5" in diameter that won't fill in at all for months and inhibits a greater area to a lesser extent. The same happens with multichips.

Also another reason I focus on the config/coverage aspect is because one could take the PAR guideline and say "I can get better PAR with a WW CW array and use less LEDs" etc etc and you would be wrong, because there is a difference in bandwidth.

My recommendation are based on not just PAR / even coverage (however you look at it). There is also a "punch" factor. When it comes a thick mat of algae, what matters as you progress further through the growth cycle each week is how much light is penetrating deep into the algae mat and keeping the base of growth alive.

Now consider that when you compare 2 different scenarios which produce the same measured intensity on the growth substrate:

1) an array of higher intensity and lensed/focused LEDs that is something like 10" away from the screen, and

2) a dense array of unlensed LEDs that is more like 1" to 1.5" away

I would argue that the latter will penetrate deeper into the algae mat and this does, IMO, make a huge difference.

Punch without burning is a balance.

[zachtos]

Originally Posted by Floyd R Turbo

For instance here is an intensity reading that someone sent me, this is an array of DRs at 2" on center with HVs in the center of each "square" of reds, with the HV at 50% relative to the DRs and the entire array dimmed to "50%" and then at full intensity



I'm not sure how this translates to PAR but what he told me was that this was measured at dead center in front of the fixture, and there was little to no difference at any other point in front of the fixture or at the end even. So I know that the coverage technique works - because hotspots cause major issues, and it doesn't take much to create a hotspot.

I found out early on with LEDs that this is the case. Take an array for a 4x6 screen that is 6 deep reds in a 2x4 rectangle pattern and then put a royal blue right in the middle of that rectangle, and put one such array on each side of the screen. The result is you will see a bare spot dead center on the screen about 1.5" in diameter that won't fill in at all for months and inhibits a greater area to a lesser extent. The same happens with multichips.

Also another reason I focus on the config/coverage aspect is because one could take the PAR guideline and say "I can get better PAR with a WW CW array and use less LEDs" etc etc and you would be wrong, because there is a difference in bandwidth.

My recommendation are based on not just PAR / even coverage (however you look at it). There is also a "punch" factor. When it comes a thick mat of algae, what matters as you progress further through the growth cycle each week is how much light is penetrating deep into the algae mat and keeping the base of growth alive.

Now consider that when you compare 2 different scenarios which produce the same measured intensity on the growth substrate:

1) an array of higher intensity and lensed/focused LEDs that is something like 10" away from the screen, and

2) a dense array of unlensed LEDs that is more like 1" to 1.5" away

I would argue that the latter will penetrate deeper into the algae mat and this does, IMO, make a huge difference.

Punch without burning is a balance.

Well, from my last LED build (3-4 years back), I used 36 LED on a 6x14" fixture with 60 degree optics and got great coverage on 12"x24", so I find it hard to believe I need double that for a turf scrubber.

The LED turf scrubber I built was about 6x6" heat sink with 9 red/blue LED (wrong spectrum, lighter red and higher blue, but it worked for chaeto, still in use). That gives 900+ PAR when only a few are on optics, it made dead spots on my test turf scrubber. If mounted farther away, it works great with lest waste light.



Not sure What I will do now since 84 LED/side is so expensive, seems odd that it comes out to +100% more than estimated. I think I will try to make LED fixture 10" from screen with wide optics to minimize light loss and just use correct spectrum and measure with my PAR meter. Can always buy more LED I guess if need. I can maybe make multi channel so I can only turn on lights on the right/left/middle so I can add more screens as my bioload grows. I have a 30" wide sump so I got the room.

[Floyd R Turbo]

One thing that might help explain the difference between chaeto and scrubber for that light fixture is water - any water penetration will kill off the red component very quickly, so what might work well for chaeto would burn the scrubber, that makes sense.

Regarding the 84/side, that is for a tight array that is really close and designed for maximum intensity under optimal conditions (scrubber sized to feeding, etc etc).

What I call out for the "minimum" of half of that (42/side = 84 total) on that same screen would still probably yield good results. You could probably trim that down further, like 25-30 per side and still get good results, same size scrubber, same distance to the screen (or maybe 3" instead of 1.5-2" and up the current a bit) for quite a while and that is because you are starting with a lower bioload than the end-goal.

Now take that and cut the screen size in half: now you're down to a smaller screen, and if you go with a bit more density than the last number, say 15-18 LEDs per side, you're at a decently sized screen with room for expansion both on the number of LEDs and the overall size of the system.

One thing to keep in mind is that my guideline is just that - a guideline. Most people that build a scrubber are building something moderately sized, like in the 7x7 range or maybe a bit bigger, and for that size, the spacing guideline will get you a lot of bang in that space. Even coverage is more critical with a smaller scrubber.

I would say that with a larger scrubber, while it is ideal to hit it with the same coverage concept, I think you start to stretch the envelope and the feeding guideline might start to break down a bit. The feeding guideline seems to hold very well for tanks fed 2, 4, 6 cubes/day etc, pretty well for tanks fed 10 or 15 cubes/day but I think much past that and you start to see a wide variance so it's hard to set in stone the size of scrubber you would need.

I'm guessing (total guess) that a graph of feeding to screen size would not be a straight line but more of an arc, where the larger your feeding becomes, the ratio might start to drop a bit (screen area might need to be less that the "12 sq in/cube/day" figure once you hit a certain point) if that makes sense. Again, not a whole lot of data, and that is also compounded by the fact that extremely large tanks (300g+) are for the most part do not have sole filtration, they have multiple forms, and all of these take up some of the load.

If everything were sized relative to feeding...it would be easy

[jrpark22000]

Originally Posted by Floyd R Turbo

For instance here is an intensity reading that someone sent me, this is an array of DRs at 2" on center with HVs in the center of each "square" of reds, with the HV at 50% relative to the DRs and the entire array dimmed to "50%" and then at full intensity



I'm not sure how this translates to PAR but what he told me was that this was measured at dead center in front of the fixture, and there was little to no difference at any other point in front of the fixture or at the end even. So I know that the coverage technique works - because hotspots cause major issues, and it doesn't take much to create a hotspot.

I'm the one who took the spectrograph for Floyd. To elaborate on why and some of his points about PAR.

I trust PAR about as much as I trust API water test kits. Both have their purpose, the biggest benefit is both are cheap. The reason I use a hach spectragraph to test water is the same reason I purchased the spectrometer, Accuracy.

The problem with PAR is two completely different spectrums can give you a similar PAR number. PAR is based on the entire photosynthesis range. As we know terrestrial plants use a different spectrum as compared to corals, look at all the red plant growers use compared to all the blue of coral growers. By taking a mathematical average of the given photosynthesis range and saying that a given PAR measurement is better suited to a given plant or coral is incorrect. Unless you’re looking at the entire spectrum (without the averaging of a PAR tool,) then tuning all the peaks of light to the requirements of the given object you are growing, PAR by itself is about as accurate as an API water test kit for po4.