BRStv....Can an Algae Scrubber outperform a Protein Skimmer?

[sixty_reefer]

What is doc?

Dissolved Organic Carbon

 

[The cats wrasse]

Ironically, algal turf scrubbers have been around as long as the skimmer has LOL. I’ve personally been running both since the early 90s. If you’ve the space and resources, I see no compelling reason to not run both.

To be honest I thought they were around before the 90s but I didnt mean since inception I was referring to their dominance in the hobby and what the "hot items"are

 

[The cats wrasse]

Dissolved Organic Carbon

You dont say I swear there's an acronym for everything in this trade

 

[Scrubber_steve]

There are are lots of living things that can absorb some metals, but they do not get removed unless you export them.

The whole purpose of a scrubber is to grow algae & then harvest it.

This is cool if your ATS is going swimmingly and you are culling a bunch all the time... otherwise they can be reintroduced if something goes wrong and the algae starts to break down.

I cannot imagine what could go wrong here. You clean the scrubber screen of the 7 day accumulated growth, leaving only what could best be described as a film of algae on the screen. It's placed back into the unit, &, after a short time - a day or so, it begins to grow again. After around 7 days the screen is ready to be cleaned again.
OK,,, what if the light failed? there'd be no growth. Even with a full screen, it would take days, or even a week or more before the algae began to die.
What if the flow stopped? The algae would desiccate. Would this kill it? Algae at the tidal zone sits out of the water for hours at low tide in the middle of the day in summer - no problem. So a pump failure would have to go unnoticed for a long time to kill the algae.

I won't argue that skimmers aren't effective at removing heavy metals, but I'm comfortable relying on my scrubber to tend to the minute amount that may enter my tank.

Biosorption: An Interplay between Marine Algae and Potentially Toxic Elements—A Review

With increasing scientific knowledge, socioeconomic awareness, human health problems, and ecological apprehensions, people are more concerned about adverse health outcomes. Against this background, several removal methods have been proposed and implemented with the aim of addressing environmental pollution and sustainable and eco-friendly development. Among them, the biosorption of pollutants using naturally inspired sources, e.g., marine algae, has considerable advantages. In the past few years, marine algae have been extensively studied due to their natural origin, overall cost-effective ratio, and effectiveness against a broader pollutant range; thus, they are considered a potential alternative to the conventional methods used for environmental decontamination.

 

[sixty_reefer]

I ran across this this morning. Its kind of good timing because I have been considering taking my skimmer offline for some time now and I think that this kind of seals the deal for me. I am one of those that has a system that runs way too clean no matter how much food is thrown in. I have a 75 gallon DT with lots of live rock, a carbon reactor, filter sock, Turbo aquatics scrubber, and reef octo 150 skimmer. With this combo I have a really hard time keeping nutrients from bottoming out. I don’t want to remove the carbon because it has a very noticing effect on water clarity and I can tell right away when its time to be changed. I recently removed the filter sock and the slight bump in nutrients had a noticeable increase in SPS PE and nutrient levels. So i think it might be time to remove the skimmer as well.


The only downside I can think of is oxygen exchange may suffer. But I have so much surface movement with an open top that I am thinking it might not be that big of a deal. My wife got me a handheld PH tester for Christmas so I am thinking to test the PH at several times during the day for a few days, take the skimmer offline, and repeat the PH tests for a few days and see what happens. Anyone else replace their skimmer with a quality efficient scrubber?

I think this tank and many others have been doing ok for a wile running skimmerless


update us on how your experience goes.

 

[Scrubber_steve]

I won't argue that skimmers aren't effective at removing heavy metals

Well, if I wanted to also be picky, I may be able to argue that the ability of a skimmer to extract heavy metals from the water would be dependant on the ability of the skimmer to remove not just particulate organic matter, but dissolved organic matter from the water.
I imagine that the dissolved heavy metals bind mostly to dissolved organic matter. Feldman's testing showed that skimmers only remove about 30% of available TOC from the water, & almost all of that was particulate matter.

So how effective are skimmers at removing heavy metals?

 

[Potatohead]

You dont say I swear there's an acronym for everything in this trade

YGTR










(you got that right)

 

[Dan_P]

I ran across this this morning. Its kind of good timing because I have been considering taking my skimmer offline for some time now and I think that this kind of seals the deal for me. I am one of those that has a system that runs way too clean no matter how much food is thrown in. I have a 75 gallon DT with lots of live rock, a carbon reactor, filter sock, Turbo aquatics scrubber, and reef octo 150 skimmer. With this combo I have a really hard time keeping nutrients from bottoming out. I don’t want to remove the carbon because it has a very noticing effect on water clarity and I can tell right away when its time to be changed. I recently removed the filter sock and the slight bump in nutrients had a noticeable increase in SPS PE and nutrient levels. So i think it might be time to remove the skimmer as well.


The only downside I can think of is oxygen exchange may suffer. But I have so much surface movement with an open top that I am thinking it might not be that big of a deal. My wife got me a handheld PH tester for Christmas so I am thinking to test the PH at several times during the day for a few days, take the skimmer offline, and repeat the PH tests for a few days and see what happens. Anyone else replace their skimmer with a quality efficient scrubber?

Thanks for the video link.

You are right about the potential of decreasing oxygen levels in the aquarium and increasing CO2 levels. BRS should study this.

The pH test will only tell you about pH and you can infer CO2 levels from this but you will not know anything about whether you are suffocating the aquarium inhabitants at night. You will need to measure oxygen levels throughout the day to understand what you might be doing to your aquarium without the aeration from the skimmer.

 

[theMeat]

Have experimented with taking each off line for a few months at a time.
When I took scrubber off line the skimmer continued to collect the same amount.
When I took the skimmer off line the ats grew much more much faster.
I run a skimmer and a large refugium now

 

[Scrubber_steve]

Thanks for the video link.

You are right about the potential of decreasing oxygen levels in the aquarium and increasing CO2 levels. BRS should study this.

The pH test will only tell you about pH and you can infer CO2 levels from this but you will not know anything about whether you are suffocating the aquarium inhabitants at night. You will need to measure oxygen levels throughout the day to understand what you might be doing to your aquarium without the aeration from the skimmer.

Eric Borneman's testing showed that -

"Aquaria can and do become saturated or supersaturated with oxygen during the day, and this is a result of oxygen resulting from irradiance of photosynthetic organisms. In no case was saturation or supersaturation measured without photosynthesis."

and

"Airstones and skimmers appear to be a very effective means of oxygenating small water volumes. Their effect on larger water volumes appears to be less. While the effect may be relative, the larger tanks and systems described here utilized powerful skimming or air pumps, and to gain an equivalent amount of oxygen as occurs in small water volumes would likely require air pumps or skimmers far larger than those commonly employed by aquarists. This includes data from a coral farm where very large commercial sized skimmers and high surface area/volume ratios failed to produce water even nearly saturated with oxygen at night with a heavy coral population."

"Powerheads and recirculating pumps do not appear to greatly increase the oxygen saturation state of seawater aquaria. Instead, they probably serve to move oxygenated waters to areas of the tank that are locally lower in oxygen resulting from respiration within the tank."

"Using algae in reverse daylight tanks appears to be an effective means of keeping oxygen levels at normoxic levels at night. This effect is pronounced even in tanks and systems that employ protein skimmers and airstones."


The Need to Breathe, Part 3: Real Tanks and Real Importance

 

[vetteguy53081]

Scrubbers are great and perform well for their expected needs.
Have one for sale and surprised no grabbers. They do the job !

 

[hart24601]

This test was a rare misstep by BRS. What they did was to test is scrubbers reduce phosphates. Which they found they did. The video should be titles “Do scrubbers reduce phosphate” or “do scrubbers reduce nutrients” although they only really test phosphate as they state nitrate is FYI due to testing troubles.

Thats it. They should not have talked about skimmers at all since they didn’t directly test them. It’s going down the exact opposite path brs videos should be going. So based off this they can rename the chaeto videos as being better than skimmers too since they didn’t test them there either. How about a gfo test showing it reduces phosphate - which it will - that can then be stated as being better than a skimmer? You can see why that labeling is problematic.

To me the arguing in this threads about scrubber vs skimmer are not warranted as to the perspective of the video didn’t test both.

I do think BRS learned it lesson here. I think they should just redo the video. The info is good, but as you can see here the message is lost.

 

[Scrubber_steve]

This test was a rare misstep by BRS. What they did was to test is scrubbers reduce phosphates. Which they found they did. The video should be titles “Do scrubbers reduce phosphate” or “do scrubbers reduce nutrients” although they only really test phosphate as they state nitrate is FYI due to testing troubles.

Thats it. They should not have talked about skimmers at all since they didn’t directly test them. It’s going down the exact opposite path brs videos should be going. So based off this they can rename the chaeto videos as being better than skimmers too since they didn’t test them there either. How about a gfo test showing it reduces phosphate - which it will - that can then be stated as being better than a skimmer? You can see why that labeling is problematic.

To me the arguing in this threads about scrubber vs skimmer are not warranted as to the perspective of the video didn’t test both.

I do think BRS learned it lesson here. I think they should just redo the video. The info is good, but as you can see here the message is lost.

I don't think that's the only problem.
Why did BRS put dead rock in all tanks ?

Look at the results for the control tanks that had no filtration, but also had dead rock.

Neither Control tank #1 or #2 when fed 1 cube a day over the 4 week period, had a rise in PO4 between weeks 2 to 3?

Again, when fed 2 cubes a day over a three week period, neither Control tank #1 & #2 had any rise in PO4 between weeks 4 to 6? Why,,, how,,, no filtration!

The control tanks PO4 readings over the 7 week period somewhat mimicked the scrubbed tanks readings in regards to an increase in PO4 after the 2 to 3 week, & 4 to 6 week periods, although the control tanks PO4 went way higher. Something else affected the PO4 levels, & I say it was the dead rock used in all four tanks.

 

[Dan_P]

Eric Borneman's testing showed that -

"Aquaria can and do become saturated or supersaturated with oxygen during the day, and this is a result of oxygen resulting from irradiance of photosynthetic organisms. In no case was saturation or supersaturation measured without photosynthesis."

and

"Airstones and skimmers appear to be a very effective means of oxygenating small water volumes. Their effect on larger water volumes appears to be less. While the effect may be relative, the larger tanks and systems described here utilized powerful skimming or air pumps, and to gain an equivalent amount of oxygen as occurs in small water volumes would likely require air pumps or skimmers far larger than those commonly employed by aquarists. This includes data from a coral farm where very large commercial sized skimmers and high surface area/volume ratios failed to produce water even nearly saturated with oxygen at night with a heavy coral population."

"Powerheads and recirculating pumps do not appear to greatly increase the oxygen saturation state of seawater aquaria. Instead, they probably serve to move oxygenated waters to areas of the tank that are locally lower in oxygen resulting from respiration within the tank."

"Using algae in reverse daylight tanks appears to be an effective means of keeping oxygen levels at normoxic levels at night. This effect is pronounced even in tanks and systems that employ protein skimmers and airstones."


The Need to Breathe, Part 3: Real Tanks and Real Importance

Good background information.

Oxygen meters are relatively inexpensive. Monitoring the aquarium water while attempting major changes to an expensive aquarium might be a good idea.

 

[Scrubber_steve]

Good background information.

Oxygen meters are relatively inexpensive. Monitoring the aquarium water while attempting major changes to an expensive aquarium might be a good idea.

sounds a good idea. I don't have any apex thingys, is there a reliable stand alone oxygen meter, perhaps a pen type, that you could recommended?

cheers

 

[Dan_P]

sounds a good idea. I don't have any apex thingys, is there a reliable stand alone oxygen meter, perhaps a pen type, that you could recommended?

cheers

Sorry, I cannot recommend a brand, but there are plenty of folks using them. Maybe someone can suggest a reliable model.

 

[theMeat]

sounds a good idea. I don't have any apex thingys, is there a reliable stand alone oxygen meter, perhaps a pen type, that you could recommended?

cheers

O2 testers are expensive. A cheaper one is a couple hundred US.
Could do a color/chemical test much cheaper. Salifet makes one. Maybe not 100% accurate but fir purposes discussed here it will be enough to gain some knowledge

 

[Mr bigolsworth]

Personally im planning to run a red sea RSK-300 and the new icecap 20W on a reefer 525XL. i want great water quality but don't want zero nutrients. Thats why i went small on both worlds. combined with filter socks i don't force an issue and if i need more nutrients i plan to just lower the run time on the scrubber.