Are algae scrubbers better than protein skimmers at removing nutrients? | BRStv Investigates

[Feet4Fish]

Always a place for cynicism for sure. IMO they are trying to they are trying to compare the ATS to a simple control (tank with no filtration) . The next step could be skimmer to control. Which will give a degree of comparison. After that they could put them head to head. One challenge for the skimmer group is all the variables - water height, air and water flow. ATS has a few variables as well - light spectrum, intensity and contact time ( water flow rate) .

My cynical guess is that the skimmer tank (alone) removed significantly less phosphates/nitrates than the ATS tank (alone) removed, so a skimmer tank (alone) wasn't included in the data because it'd make the skimmer look bad, and skimmers are money makers.

 

[Njbjr]

Plenty of people have done comparisons to a skimmerless tank vs a skimmed tank. So, if one tank has no scrubber and the other tank has one, now you have a common baseline of sorts. It's not a perfect parallel but it's a start

As the OP says:



There have literally been zero benchmark studies to measure the effectiveness of an algae scrubber in a hobbyist level aquarium, in the current form/design that is. No universities, etc. Just 40 year old info from Adey, that's as close as we can get.

The rest of the info out there is anecdotal by majority. So before everyone starts chucking axes at @Bulk Reef Supply let's just start with the fact that they are doing decent studies on this kind of thing and we should, as a hobby, thank them for taking it to that level. I've been in the area where they are testing things, it's like a hobbyist's dream lab man...I saw this test setup when it had only been up and going for a few weeks and I've been anticipating the results.


They're a business, of course they're going to promote products that they carry. Think about it this way though, if they wanted to advertise scrubbers, wouldn't they just grow one out and take a bunch of pics of servicing it and such? Why would they set up a controlled environment composed of 2 test tanks and 2 control tanks on Neptune dosers and controllers to do the same thing they could have done on 1 tank? Don't tank that they wrong way, I'm not trying to by rude or snarky or anything - my point is as started above - they are going beyond the anecdotal.


IMO system biodiversity has as much to do with growth on an algae scrubber as do nutrients. As long as you are feeding on a regular basis and have a bioload in the tank producing waste, you'll have growth, even when nutrients appear to be bottomed out.


I've been on both sides of this fence. Initially, when I first started using a scrubber, I was anti-skimmer and anti-water change. Now that I have a little more white in my beard I understand that there is a lot of middle ground.

I wouldn't go as far as saying they are "meant" to complement each other, but rather that they can in certain situations. In other situations, they can replace one another.

Julian Sprung's video on this topic is really the best way to cover this.






We have tests that a skimmer can remove X compared to a tank without. I don't think the intent was to compare the 2 directly...just have some data to even discuss - at least that's how I see it. I have a ton of anecdotal examples of scrubber effectiveness but no one gives a rats behind about actually running a study, and I understand why...


Maturation time has always been 4-6 weeks for bare plastic canvas, but it is also highly dependent on the system (age, bioload, etc, etc). I've had customers with one of my scrubbers have it take 4 months to get enough to call "growth" and others that had a full growth chamber in 15 days from scratch (with no screen seeding).

Thanks for being respectful and I mean no I’ll feelings towards you or brs. They have helped me a lot with products and improved the hobby so much it can’t be said enough. The experiment only validated the product and was not titled properly. Why not do a comparison video like they did and say at the end of the video ; their next step of scrubbers against skimmers next. I would lalso caution the 10 on reef certainty especially vs refugiums.
Finally I will admit seeing brs through the years joining the dark side and seeing the effectiveness of a refugium. They have adapted well and I will look for their progress.

 

[Njbjr]

T

Always a place for cynicism for sure. IMO they are trying to they are trying to compare the ATS to a simple control (tank with no filtration) . The next step could be skimmer to control. Which will give a degree of comparison. After that they could put them head to head. One challenge for the skimmer group is all the variables - water height, air and water flow. ATS has a few variables as well - light spectrum, intensity and contact time ( water flow rate) .

There is gonna be the added problem of how to fix a scrubber day a light burns out or broken pieces. There is no supply for maintenance or repair. A refugium or skimmer will have these needs in droves.

 

[Feet4Fish]

Lights replacement/upgrade doesn’t provide much of a challenge really. Current manufactures would happily seek you a light and even if they were to fold plenty are available out there that can suffice. Replacement “parts” would be various PVC fitting and acrylic work. Maybe a little more aloof for some but not insurmountable. Many out there DIY these bad boys for a couple decades and the foundation has been laid out well on how to construct and modify them.

T

There is gonna be the added problem of how to fix a scrubber day a light burns out or broken pieces. There is no supply for maintenance or repair. A refugium or skimmer will have these needs in droves.

 

[Njbjr]

Lights replacement/upgrade doesn’t provide much of a challenge really. Current manufactures would happily seek you a light and even if they were to fold plenty are available out there that can suffice. Replacement “parts” would be various PVC fitting and acrylic work. Maybe a little more aloof for some but not insurmountable. Many out there DIY these bad boys for a couple decades and the foundation has been laid out well on how to construct and modify them.

DIY isn’t the answer to this cause people would diy from the beginning if they could or wanted to repair them. And for parts I agree with manufacturers.

 

[JoshH]

Always a place for cynicism for sure. IMO they are trying to they are trying to compare the ATS to a simple control (tank with no filtration) . The next step could be skimmer to control. Which will give a degree of comparison. After that they could put them head to head. One challenge for the skimmer group is all the variables - water height, air and water flow. ATS has a few variables as well - light spectrum, intensity and contact time ( water flow rate) .

This issue is they ended the video by rating the "Is a scrubber better than a skimmer at removing phosphate and nitrate" question by saying yes. This effectively ends the comparison without actually providing numbers from the skimmer side atall. I agree a natural progression would be to run skimmers and a control but they made no indication of such a future test atall.

As I mentioned earlier, I do love BRS' videos and they can be super helpful, I just feel this one may be a little misleading...

 

[robbyg]

Plenty of people have done comparisons to a skimmerless tank vs a skimmed tank. So, if one tank has no scrubber and the other tank has one, now you have a common baseline of sorts. It's not a perfect parallel but it's a start


There have literally been zero benchmark studies to measure the effectiveness of an algae scrubber in a hobbyist level aquarium, in the current form/design that is. No universities, etc. Just 40 year old info from Adey, that's as close as we can get.

Yes I agree, it was a good test in the regards to ATS versus a tank without anything, but of course it throws the video title right out the window.

The rest of the info out there is anecdotal by majority. So before everyone starts chucking axes at @Bulk Reef Supply let's just start with the fact that they are doing decent studies on this kind of thing and we should, as a hobby, thank them for taking it to that level. I've been in the area where they are testing things, it's like a hobbyist's dream lab man...I saw this test setup when it had only been up and going for a few weeks and I've been anticipating the results.


They're a business, of course they're going to promote products that they carry. Think about it this way though, if they wanted to advertise scrubbers, wouldn't they just grow one out and take a bunch of pics of servicing it and such? Why would they set up a controlled environment composed of 2 test tanks and 2 control tanks on Neptune dosers and controllers to do the same thing they could have done on 1 tank? Don't tank that they wrong way, I'm not trying to by rude or snarky or anything - my point is as started above - they are going beyond the anecdotal.

I love their videos but you have to draw a line between product promotion and actual scientific results. They need to be very careful when running any test if they are going to declare it using a "Reef Certainty Scale". I would not give a crap how they rated something if they said it's on the BRS Certainty scale, but once they cross the line and say they are eliminating all other anecdotal evidence to the contrary "by other reefers". Then IMO they had better do it openly and without any bias towards one method or one product.

IMO system biodiversity has as much to do with growth on an algae scrubber as do nutrients. As long as you are feeding on a regular basis and have a bioload in the tank producing waste, you'll have growth, even when nutrients appear to be bottomed out.

Well I guess most of us know that you cannot have Algae growth unless you have nutrients. That is one of the reasons why a planted refugium and ATS have never been on my to do list.

I've been on both sides of this fence. Initially, when I first started using a scrubber, I was anti-skimmer and anti-water change. Now that I have a little more white in my beard I understand that there is a lot of middle ground.

I wouldn't go as far as saying they are "meant" to complement each other, but rather that they can in certain situations. In other situations, they can replace one another.

IMHO the middle ground only exists when the nutrient levels are low enough that the ATS can handle the Phosphate and Nitrate that is produced from the remaining organics in the water. If the nutrient level goes any higher you get what you will probably see in the next video "When The Lights Are On!" I predict significant Algae growth even in the Tank with the ATS. A skimmer would have reduced the coming growth by a lot more.

Julian Sprung's video on this topic is really the best way to cover this.

I don't know if I have watched this one yet but JS typically runs very low nutrient based systems with very low bio loads and lots of items like Mangroves and very active DSB's to get around many situations that other people would have problems with.

We have tests that a skimmer can remove X compared to a tank without. I don't think the intent was to compare the 2 directly...just have some data to even discuss - at least that's how I see it. I have a ton of anecdotal examples of scrubber effectiveness but no one gives a rats behind about actually running a study, and I understand why...

Well I think they should have changed the title of the video and thread because that is exactly what they claimed to be doing.
"Are algae scrubbers better than protein skimmers at removing nutrients? "

Maturation time has always been 4-6 weeks for bare plastic canvas, but it is also highly dependent on the system (age, bioload, etc, etc). I've had customers with one of my scrubbers have it take 4 months to get enough to call "growth" and others that had a full growth chamber in 15 days from scratch (with no screen seeding).

This part did not bother me. We know how they got there and it saved time. Maybe they could have just used a one line statement saying they had the ATS systems running for six weeks before on another tank system. Not all that important IMO.

 

[randyBRS]

I think Ryan summed this up the best in one of his responses on YouTube. Basically, there's no doubt we could have been more clear about how we came to the skimmer vs. scrubber comparison, but when it comes down to it I'm sure that a vast majority of us could agree that a skimmer won't effectively remove 100% of the organics and related nutrients.

"In the case of this test, the scrubber did remove basically all the nitrate and phosphate from the single cube addition and larger size scrubbers presumably will scale with that. Performance most reefers would agree is nearly impossible with a skimmer alone.

The reason we didn't test against an actual skimmer is because that’s akin to testing the speed of “a car” Brand, size, tuning, maintenance and even type or track all dramatically effect performance. No matter what we used or how we used it would not give a very accurate depiction of performance on the average tank. That said in a separate test it might be fun to set up a few different skimmers and test what percentage of the organics they remove.

It won’t tell us anything definitive but it will crack the door open and provide a window into potential performance. "

 

[Turbo's Aquatics]

Thanks Randy - for the response and for everyone at BRS running the test - and all these types of tests you do

 

[hart24601]

I think Ryan summed this up the best in one of his responses on YouTube. Basically, there's no doubt we could have been more clear about how we came to the skimmer vs. scrubber comparison, but when it comes down to it I'm sure that a vast majority of us could agree that a skimmer won't effectively remove 100% of the organics and related nutrients.

"In the case of this test, the scrubber did remove basically all the nitrate and phosphate from the single cube addition and larger size scrubbers presumably will scale with that. Performance most reefers would agree is nearly impossible with a skimmer alone.

The reason we didn't test against an actual skimmer is because that’s akin to testing the speed of “a car” Brand, size, tuning, maintenance and even type or track all dramatically effect performance. No matter what we used or how we used it would not give a very accurate depiction of performance on the average tank. That said in a separate test it might be fun to set up a few different skimmers and test what percentage of the organics they remove.

It won’t tell us anything definitive but it will crack the door open and provide a window into potential performance. "

I do very much appreciate the tests and the postings. With the impact you have had and the increasing influence you have on the knowledge base and reefers I think you need to be vary careful with statements like this video. I still don't agree with that explanation on the wording of this video - I personally feel that the attempts above to justify are off the mark a bit. IMO it's best just to clear up this test had nothing to do with skimmers at all and it was misstated.

Even the response above "The reason we didn't test against an actual skimmer is because that’s akin to testing the speed of “a car” Brand, size, tuning, maintenance and even type or track all dramatically effect performance" - But you can give the test a 10 out of 10 saying scrubbers are better at removing nutrients? What that leads to is saying that all the above matters for a skimmer, but none of that matters because 10 out of 10 a scrubber is better.

 

[randyBRS]

I do very much appreciate the tests and the postings. With the impact you have had and the increasing influence you have on the knowledge base and reefers I think you need to be vary careful with statements like this video. I still don't agree with that explanation on the wording of this video - I personally feel that the attempts above to justify are off the mark a bit. IMO it's best just to clear up this test had nothing to do with skimmers at all and it was misstated.

Even the response above "The reason we didn't test against an actual skimmer is because that’s akin to testing the speed of “a car” Brand, size, tuning, maintenance and even type or track all dramatically effect performance" - But you can give the test a 10 out of 10 saying scrubbers are better at removing nutrients? What that leads to is saying that all the above matters for a skimmer, but none of that matters because 10 out of 10 a scrubber is better.

Absolutely a valid point. In hindsight, this was the first Investigates where we didn't really compare hard data to hard data and we could have done it better. If this situation were to come up again I will definitely be more cognizant of the weight/certainty that comes with a 10/10 rating as well as more thoroughly explaining the reasoning behind our comparison. We live, learn and get better.

 

[hart24601]

Absolutely a valid point. In hindsight, this was the first Investigates where we didn't really compare hard data to hard data and we could have done it better. If this situation were to come up again I will definitely be more cognizant of the weight/certainty that comes with a 10/10 rating as well as more thoroughly explaining the reasoning behind our comparison. We live, learn and get better.

And as always we very much appreciate the work you do (the whole BRS team). We are being so picky because that is how high you all have raised the bar!

 

[robbyg]

I also appreciate the Videos.
I think a simple solution would be to change the name of the Video to "Can Algae Scrubbers Alone Remove Nutrients To Safe Levels." That way the title would be accurate to the content and the 10 out of 10 certainty score would still be somewhat valid. I say Somewhat because I have a feeling when the lights in the Tank come on, the answer might not be a full 10 out of 10.

 

[hart24601]

I also appreciate the Videos.
I think a simple solution would be to change the name of the Video to "Can Algae Scrubbers Alone Remove Nutrients To Safe Levels." That way the title would be accurate to the content and the 10 out of 10 certainty score would still be somewhat valid. I say Somewhat because I have a feeling when the lights in the Tank come on, the answer might not be a full 10 out of 10.

I think that would be a good change. If I really want to be picky I would say that we are not even looking at 'nutrients' but only phosphate. The video even said nitrate was more just FYI since it doesn't test very accurately. "Are scrubbers effective phosphate export" the video clearly shows they can be! I am behind that 100% based off the video.

 

[JoshH]

Absolutely a valid point. In hindsight, this was the first Investigates where we didn't really compare hard data to hard data and we could have done it better. If this situation were to come up again I will definitely be more cognizant of the weight/certainty that comes with a 10/10 rating as well as more thoroughly explaining the reasoning behind our comparison. We live, learn and get better.

And as always we very much appreciate the work you do (the whole BRS team). We are being so picky because that is how high you all have raised the bar!

I agree, it's not that the work isn't appreciated it's that Ryan and Randy do have such a large following that things tend to warrant a little extra scrutiny.

A lot of reefers frequently look to BRS videos for solid and accurate advice on everything reefing related. And more still refer new reefers directly to them to get started which is awesome and why these videos are so important. And in saying that I feel things do need to be as on point as possible. Randy you have indeed raised the bar on reefing videos and we want to see you keep taking it to new heights in the future.

I hope that you do come to realize that these "Reef Certainty" ratings can indeed have a huge impact on how some see certain aspects of the hobby, especially newer hobbyists. And the weight of the information shared in your videos may go further than you think.

 

[Colin_S]

Great video, and really informative for us all, especially if new to the hobby. Couple of points;
I was a bit confused that no skimmers were used to compare, and secondly i assume most people run refugium + Skimmer... i would like to see how the ATS compares to Chaeto with both running skimmers and without skimmers then we could have some nugget of thought about whether or not we could go skimmerless.
I tried growing chaeto for my Triton method and had no success, so switched to ATS.
Forget the pros and cons as this is a different disgussion, but to compare the two,Chaeto v ATS at nutriant control and give people that are not as well informed an option and the info needed to make a choice.
Maybe that person can't have a refugium for what ever reason and think that they can no longer run any ultra low maintance system because of this, well in fact a more compact ATS might be as effective, less effective or better than a refugium. Then what ever the outcome is they can decide on whats best for them and if you can have a fuge you might want a different option taking into account of all the pros and cons.
Even writing this i can think of a few issues that will have people talking about. Established tanks v new tanks, fish stock load and feeding habbits will all affect the results. But its a start and with all the other helpfull videos and articals out there we could have some really good advise.

 

[Maxx]

@randyBRS

You guys mentioned the pH bump from a cheato refugium several times in your videos over the years and also mentioned that the ATS would most likely not increase the pH due to pulling CO2 from the surrounding air vs the tank's water. Have you guys noticed any pH changes at all while using the ATS?

It would be an interesting side bar to compare the pH changes from both a refugium and an ATS, and then contrast the two.

 

[Njbjr]

@randyBRS

You guys mentioned the pH bump from a cheato refugium several times in your videos over the years and also mentioned that the ATS would most likely not increase the pH due to pulling CO2 from the surrounding air vs the tank's water. Have you guys noticed any pH changes at all while using the ATS?

It would be an interesting side bar to compare the pH changes from both a refugium and an ATS, and then contrast the two.

That is an excellent question.

 

[randyBRS]

@randyBRS

You guys mentioned the pH bump from a cheato refugium several times in your videos over the years and also mentioned that the ATS would most likely not increase the pH due to pulling CO2 from the surrounding air vs the tank's water. Have you guys noticed any pH changes at all while using the ATS?

It would be an interesting side bar to compare the pH changes from both a refugium and an ATS, and then contrast the two.

I actually did follow the pH on this one as well, but left the data out as to not muddle the conversation around PO4/NO3.

You are right this is interesting data to share, however there really wasn't anything significant there. All four tanks averaged nearly identical pH throughout the duration of the test. Anecdotally I would say that this somewhat confirms the theory of ambient CO2 rather than the tank, but probably something we could revisit in one of our followup tests.

I know for sure that if/when we compare the ATS directly with a refugium, pH will be one of the metrics we monitor.

 

[Maxx]

I actually did follow the pH on this one as well, but left the data out as to not muddle the conversation around PO4/NO3.

You are right this is interesting data to share, however there really wasn't anything significant there. All four tanks averaged nearly identical pH throughout the duration of the test. Anecdotally I would say that this somewhat confirms the theory of ambient CO2 rather than the tank, but probably something we could revisit in one of our followup tests.

I know for sure that if/when we compare the ATS directly with a refugium, pH will be one of the metrics we monitor.

Thanks Randy.
I'd be very interested in the results.