[FlyPenFly]

Yes, I've read a lot previously about how once the phosphate absorbing capacity of sand is reached the system can go Eutrophic. I don't entirely buy this although I think the theory is sound. You're just removing one component of phosphate export, I'm not sure why that would make the whole system go bad. If this is really a problem, it seems an easily removable container with some sand and dry rock is a cheap easy solution to this problem. Just place in sump and replace as necessary just like you would carbon or any other media absorber.

I still don't see any evidence on how macro or turf algae growth though is necessarily poisonous for an aquarium as indicated earlier in this thread. If the claim is that any algae growth means the system is not doing well, I just don't find that to be believable from my direct experience and observations of many tanks as well as the wild. It seems to me that algae overgrowth on a display tank is indeed a big problem in that something is out of whack. Even in brand new systems with new rock and new sand with a very low nutrient load, you still see some algae growth.

However, a turf algae scrubber seems like a very legitimate and strong method of nutrient export to me. It's lit 20-22 hours a day sandwiched in intense light designed for algae with a very high water flow rate and gas exchange. Its essentially a small enclosed device designed to outcompete the tank and other filters for turf algae growth. This biological mass is then removed from the system. Once established, the amount of algae you remove per week can be quite a lot.

From my use of ATS in the last few months, it's a lot more reliable and consistent in nutrient export than the various skimmers I've used. A well running ATS don't overflow dumping skim mate back into the system, have inconsistent collapsing bubbleheads, do not micro bubble, etc. I guess I'm in a weird middle ground where I don't think a skimmer should be the sole direct exporter and neither should an ATS. I think it's possible they're removing various different organic compounds and waste products that are being added.

 

[FutureDoc]

If the theory is sound, where is the catch?

In theory you could use sand as a phosphate binder just like GFO. However, bacteria are able to extract from Ca based material a bit easier than ferric material, so there is some practicality with that. However, that is one reason why it is recommended to change the substrate every so often.

Algae can release have an effect on coral as two of the PDFs demonstrate. However, the issue of eutrophication is a different topic. Many corals (like SPS) have evolved to survive and thrive in a relatively nutrient-limited environment. That is one reason a "animal" contains autotrophic organisms within its tissue. The coral gets the sugars and the Zoax. get the byproducts creating a nice small sustainable nutrient loop. When we talk about eutrophication, the existence of algae is not the problem... it is population boom (of algae) that is the proplem. Algae will exist, but it should existing in a limited stable or declining biomass (NOT growing). Think of it as a large apartment complex. Cockroaches will exist... it is a issue when those populations boom. Thus the small amount of algae surviving in my tank in small tuffs is not an issue. That is fine and normal. It is when algae is gaining biomass when something is "wrong" with the tank. Thus growing algae is not a mechanism for sustainable nutrient export and it is an indicator that the system is becoming eutrophic. Harvesting the algae is not a 1:1 removal of the increased nutrient load. Bacteria, pods, worms, and other organism are also gaining in mass so the process is only going to snowball as more bacterial mass = more bacterial activity which could free up more bound material to the algae and make the nutrient loop faster and tighter. In our tanks, we only really want the corals and the fish to gain mass, everything else is "waste". Thus we feed specific items, but after that, we want to disrupt the nutrient flow as much as possible. This is the problem with an ATS. If grow it, you must make nutrients very abundant. You have to make sure that there is enough P after the sand/rock/skimmer to bind P and then still have some left over for the ATS. If the ATS scrubber is growing continuously, then there is an ever increasing supply of nutrients and there is "waste" along the system so that gain is never totally accounted for by extracting algae. The bacterial mass is completely ignored. The only real way for the algae to be completely an export in a stable system is if the algae mass is 100% removed and does not grow back. If it grows back then the system is still becoming eutrophic.

It is very important NOT to assume that algae out-competes everything. It does NOT. Algae can out-compete coral, but not bacteria. That is why carbon-dosing can combat algae because bacteria are better than algae at accessing nutrients.

Here is a graphic of the phosphate cycle... it does not catch every vector but it has the major ones. Hopefully, you can see that algae is just one small grouping and P control via algae misses a lot. Same with the skimmer. The skimmer only has access to a limited amount. However, a skimmer can not over-remove (neither can algae) as the skimmer is not dependent on P for its survival. Algae is, so it will never remove P to a limiting state...a skimmer can help get to that point. If P is limited, algae will be severely limited, not growing.

 

[Floyd R Turbo]

Ok here is where I jump in, because I have a perfect example of a tank that defies part of what you just stated. It is a 144 mixed reef that has been running in it's current setup for 2 years, running only an algae scrubber. Prior to that, it was in a tank that cracked and all livestock was moved to a temp tank for 6 months, again, only algae scrubber. Prior to the tank crack, scrubber only for about 6 months, so overall 3 years scrubber only. I'm not saying that is "the answer" because I continue to learn all I can, just giving you a background in reference to part of your last post that I will address with this example.

Prior to all of this, the tank was up and running for at least 5 years. Tank had been moved once during a renovation, and when I first started maintaining it, the nitrates were over 100 and phosphate was off the charts. I spent several months getting things back in line, running socks, skimmer, water changes, etc. Used some ROWA to drop phos as much as I could. Was going to add 'fuge but that's when I read about the scrubber and went down that road instead, years later here we are.

This tank never went through an outbreak of algae on rocks or sand at any point. Perhaps because of the presence of herbivores. Anyways....on to my point now.

about 3-4 months into the current setup state of this tank, I was running a large scrubber, about 16x6 with 4 T5HOs. I replaced that with a 4" x 6" LED unit. Within one month, my P, which had stayed right around 0.09-0.15 typically, dropped to 0.00 on a Hanna meter. Since then, I have never ever been able to get a reading over 0.02.

The algae in the scrubber still grows, it is almost dead on consistent in color, volume, mass, across the board for the last 1.5 years.

Overall, coral growth is not what I would call explosive, but this is a tank in an office and I don't really care to be pruning it monthly, and there is nothing dying that wasn't overgrown by another neighboring coral.

So I just don't get how if everything you are saying is true, how I can find multiple instances where the results defy your logic.

Just for the record here I'm all about knowing exactly how things work and why, and not gathering tidbits to highlight so I can promote a one sided agenda. If I'm going to answer someone's question when it's posed to me in the role of an "Algae Scrubber Expert", then I darn well better know what I'm talking about.

I find that so many of the anti-arguments, as well as pro-arguments, are all based on studies that cannot be paralleled because of the nature of the study, in that they are not studying a close aquarium but rather some effect in the open ocean. Unfortunately, there are no (or few) studies about current types of algae scrubbers so gleam truly pertinent information from. So anecdotal evidence is used to make a point or come to some semblance of a conclusion, and then detractors fall back on studies to disprove those conclusions. All I'm saying is that such logic seems faulty, and that I wish I had a bajillion dollars to actually study this subject for real, because I would like real answers and not just drawn conclusions based on what seems logical, on both sides of this issue.

 

[FutureDoc]

Welcome to TRT Floyd. :beer:

One of the best cases of an ATS "fail" is the Smithsonian's tank. There should be a thread about it somewhere, maybe in the "Think Tank". Tanks can hang around for years with a ATS but the ATS is not doing any favors. Other things such as detritus removal, skimmers, wc will extend the life of the tank but it is not that the ATS is doing anything other than responding to eutrophic conditions.

The biggest issue with ATS and algae proponents is that it defies the most basic underpinnings of system ecology. So, either the field of ecology is seriously flawed or that algae/fuges do not do what many claim, and that is limit nutrients.

BTW, algae is really good at converting inorganic P which we can test for although that is not to the point where algae is limiting (0.005ish ppm within a confident range of error) and converting it into organic P that we CAN NOT test for. 0.00 does not mean you do not have phosphate, rather that your test can pick them up.

In this hobby, we have limited (if any) independent peer-reviewed resources. Avoid the Nivana fallacy of seeking "perfect" answers. Work with the best information and move on. In this case, works within marine and freshwater ecology publications are more useful than trade publications. However, if the academic articles (NOT trade articles) lend support to a particular perspective, then do not claim "it is not perfect" or that it does not apply. Freshwater ecology actually applies very well in some regards as our systems mimic a freshwater small-basin water body more than the ocean. As a result we can take the ecological models and apply them to the tank. It works very well, especially if you use bioindicators. Marine ecology is a bit different as you have to be more careful about the size of the nutrient loops.

 

[Floyd R Turbo]

Someone else I know would jump immediately here and say that organic P is food. LOL

Here's what I don't follow when you say tanks can hang around for years with a scrubber but the scrubber isn't doing any favors, and that the scrubber is only responding to conditions. It comes down to the most basic tenant and that is export. I can take a harvest of algae and have it scientifically analyzed and tell you it's exact nutrient content. That content HAD to come from somewhere. I removed that amount of nutrients from the tank when I harvested. Then, it grew back in a given amount of time. I repeat this over and over again as I measurably watch testable levels drop. How is this doing nothing else but "responding to conditions"?

I will say that I have definitely seen situation where the algal growth type drastically changed. One such phase was in the aforementioned tank. The big screen stopped growing thick and green. When I switched to the smaller screen, it has maintained consistent growth. I attributed that to the tank getting "cleaned up" and no longer needing a large screen - only one sized appropriate for mopping up what was being added to the tank (food). But I'm open to other possible explanations, considering the source of that explanation.

 

[FutureDoc]

Organic P is food... bacteria love it. Bacteria then seek out carbon in our tanks (and algae will provide some). They extract carbon from the CaCO3 and release more phosphate in the process. More bacterial mass is just more potential "chefs" for algae to continue growing. See the back and forth between the two. The trick is that we add organic P (in the form of food) and then we have to wait around for it to be processed by the bacteria into inorganic P so that algae can use it. Why wait around and just siphon out the mass (as poo) when it becomes available. Why wait for bacteria to clean you dishes...

Can you really isolate the exact algae and not additional bacteria and detritus also within the turf mat. Can you then correctly analyze the food (ad organic particles like dust) entering the system to match if the ATS is also removing the same amount? If you can, great but you still missed a step. You still need the organic levels to be high enough to spur algae growth to begin with. Nip it in the bud and prevent the nutrient load from becoming high enough to have a sustainable ATS and you do not have to have to the same nutrient export... ATS is kinda like liposuction as a method of weight control. You become fat only to export the mass later while exercise and diet (ie husbandry/siphoning/wc) prevent weight gain to begin with.

The presence of growing algae in the tank does not mean the level are "dropping" they are increasing in the system. Algae is making "testing" problematic, basically giving you a testing error as what you are trying to test for is no longer in that form. Algae is a bioindicator. It grows when there is the available N and P to use. Limit one and algae will decline. If algae is continuously growing then neither N or P becomes limiting as it is in a nutrient poor environment like a reef-crest zone.

 

[Invic]

The idea of algae removal for exporting is pretty basic, and appears to make sense. Even when you look at research being done on algae farming the large amounts of nutrients that can be held with in a algal cell is quite impressive. This is often the numbers and volumes listed in discussions on algae or ATS setups. The problem is these are not volumes we will experience with a tank also supporting corals especially LPS or SPS.

After you read into the research and methods on algae farming ect. The main condition they have to focus on is nutrient loading the algae to achieve those numbers. Which they should the nutrient content = profit, its productivity for their product. What strive for is the opposite of what we want in a reef tank. Basically algae farmers have learned the maximum possible contained nutrients within algae is direct proportional to the level of nutrients in the environment it is growing in. This is one reason Algae farms are constantly adding nutrients. High nutrients levels = more contained in the cells. Low nutrient levels = Cells contain far less. 50 pounds of algae, in high level nutrients contains enormous amounts of biofuel. Where 50 pounds out of low nutrients contains very little nutrient work actual processing.

So what this means is the higher levels present in the water around the algae, the algae will take in more and push growth. Algae's biomass volume strives to match the surrounding environments nutrient supply. Now in a healthy reef, algae is virtually non existent in large biomass clumps, this is simply due to it cannot and will not expand beyond the present nutrient levels.

So lets look at a Reef level of nutrients and algae is barely present. The opposite of nutrient loading and nutrients are very low. Well algae does not have the materials to grow. Now what happens to a algae biomass when nutrient levels fall below its current biomass. Algae cells slow reproduction, due to less materials to build new cells, as well as its a self limiting mechanism. So as it slow cell reproduction the rate of cell decay remains constant, or usually increases to some starvation. Cell decay is always going on but in a low nutrient levels it is more present. Since you have cells in a stable or starvation low nutrient realm the decay is feeding nutrients back into the environment.

So when you get a low nutrient system, algae or an ATS in the system can work against you as you try to lower the nutrient levels. As you remove waste, the algae begins a starvation cycle, releasing more nutrients. Its not a mass die off its just thinning the older cells and replacing what was lost. Now since the algae was in lower nutrient realm regardless they contain very little nutrients in comparison heavy nutrient environments (algae farms ect) So as your harvesting your not removing as much as we think.

The idea of algae using up phosphates is also a bit misleading. Algae only takes in as much phosphate as it needs to operate at the level of the surrounding nutrients. Now what does it do with phosphates? Well the phosphates are converted to ATP (energy) and the ATP is spent and burned. The Phosphate is not destroyed or becomes part of the cells afterward, Spent ATP turns to ADP. ADP is then recycled back to ATP via photosynthesis. The phosphate is not lost its constantly reused. So the need for more phosphates is not required once its at operating levels which is determined by surrounding environment levels. As its not a consumed and stored resource its levels are static due to it being just recycled.

The idea of organic Phosphates are food is true, they are food. But by the same token to much food can poison anything, corals especially. To much food throws the symbiotic balance within a stony coral out of sync. The zoox increase their processing and their waste which the coral uses accelerates and more is produced then the coral can process. The build up poisons the coral. Their symbiotic relationship has its limits and can end breaking and causing the coral death or harm.

Another aspect of Organic Phosphates is they do not stay organic as you said their food. So many types of pods, bacteria, and more can consume the organic phosphates. The direct result of them eating this "food" is they convert the organics phosphates back into inorganic phosphates. Inorganic Phosphate as we know binds to calcium carbonate (rock, coral skeletons) This alone can cause for coral health issues. As well as the Organics now Inorganic are the fuel for more algae, bacteria and overall bioload /biomass in a system. Bacteria are faster at up take then algae, so the rate of transfer when organic or inorganic levels drop can be very fast and the conversion is pretty much on going.


As for ATS alone systems, I've not seen a well documented one last more then a few years, unless the cleaning routines and water change routines are increased greatly. I have watched quite a few personally run fine for a year or two and then end up in the realm of euthrophication. Most all ATS system have a good deal of support equipment also working, which adds more variables and not a sole ATS system. The same goes for usage of bacteria supplements ect. I keep my eye out all the time for any I see someone start, as to watch it progress and get more details and documentation of its life. If one were to make it down the long haul it would be interesting. Local reefer tried one that died two months ago. It was an experiment a few of us wanted to do. 20g tank sole ATS and 50% water change every week. It did well but the rock ended up loading phosphates and it took 8 months but it turned into a golf course in the end lol.

Gotta make a store run for the Mrs.

 

[chrisfrat]

The idea of algae using up phosphates is also a bit misleading. Algae only takes in as much phosphate as it needs to operate at the level of the surrounding nutrients. Now what does it do with phosphates? Well the phosphates are converted to ATP (energy) and the ATP is spent and burned. The Phosphate is not destroyed or becomes part of the cells afterward, Spent ATP turns to ADP. ADP is then recycled back to ATP via photosynthesis. The phosphate is not lost its constantly reused. So the need for more phosphates is not required once its at operating levels which is determined by surrounding environment levels. As its not a consumed and stored resource its levels are static due to it being just recycled.

I feel like an appropriate sidebar here would be the law of conservation of matter (and energy). These laws simply state that neither matter nor energy is created or destroyed. It only moves into and out of systems. This applies to Invic's argument with ATP (adenosine triphosphate) and ADP (adenosine diphosphate). The third P is added back in the light reactions of photosynthesis. In the human body, each ATP molecule is recycled 500 to 750 times every day. Since ATP cannot be stored, it is used very quickly after it is synthesized.

What I'm saying is, the P just keeps getting reused and can only be actually removed from the system by you.

 

[Floyd R Turbo]

I just don't understand something here. I know people who test N and P at zero all the time and they actually get better algae growth. In just about any instance in which one nutrient (N or P) is zero and the other is not, algae growth still occurs. One nutrient is limiting the uptake of the other, but not to the point of no algae growth. That's because unless you stop feeding the tank, you still have a source of nutrients. What I have found is that it's very difficult to truly limit N or P unless you are using another aggressive mechanism.

I agree that algae is a bio indicator but I disagree with your take on it, based on my experience. Which is that the growth color get brighter and volume/mass actually increases when nutrients are driven to very low levels, and that this type of growth actually performs better. As a result, I have been saying that the type of growth one gets is actually an indicator of how healthy their system is. The thicker and brighter green the type of growth, the healthier their system is becoming. And it does indeed work that way from most of the results that I have seen.

As far as algae in the system meaning levels are increasing, yes if in the tank and that would be an indicator of something being wrong, but a scrubber is not in the tank, it's remote, dedicated to the purpose. Why not just ditch all macro refugia concepts while we're at it because of this fundamental flaw in concept, is that basically what you're saying?

I don't understand how you can say that the mere presence of algae anywhere in the system is an indicator that levels are increasing. It really doesn't get any simpler to me than add food, algae grows, you remove it, add more food, algae grows again, you remove it. How is this not effective?

If these was some kind of big gaping hole in this process, I think I would have seen it by now with as many tanks as I run using one and with as many people whom I have given advice to in order to help them get their scrubbers working. I think I would have had someone, anyone, say that even though their tank running a scrubber with N & P fully under control and no nuisance algae in display tank to speak of suddenly took a huge nose dive. So whatever you say, you're going to have to convince me that there is some big cliff that we are all 100% inevitably headed toward.

Maybe you're just trying to use extreme examples to drive the point home that the Algae Scrubber concept is not all it's cracked up to be. Maybe you chose to take that stance because of someone else who took the polar opposite stance of "it's all you need, ditch all your other equipment" and you want to dissuade a newbie from falling into that trap by fish-slapping them back into reality. And that's fine, but that's not the full truth either.

But let's be honest here. Can you really, honestly say that everyone who is using a scrubber - regardless of what other methodologies they are also implementing - are just kidding themselves?

 

[Floyd R Turbo]

Invic that is a good post, gonna have to follow up on that one with you later. Likewise, I have to run...

 

[FlyPenFly]

I don't know, I've seen tanks that have been run for a few years also crash, in fact, quite a lot. They were however not running ATS but doing the traditional skimmer/GFO/wc route. They did suffer from what a lot of people call "Old Tank Syndrome". I don't think it's fair to say that systems running just ATS crashed because of ATS after a few years when we don't really know why some tanks that have nothing to do with ATS also crash. It's kind of like saying people who wear loafers get heart attacks... well people who wear sneakers also get heart attacks. It's inconclusive whether the crashes came from running ATS or not running ATS.

I'm also not entirely bought on the theory that substrate is the key factor in avoiding euthrophication. Bare bottom tanks also crash and tanks with substrate replacement also go euthrophic. I bet the real cause is something simple and stupid like not having a hood to avoid dust or after a few years maybe the hobbyist loses interest, etc.

To me, the game is to remove as much of the waste material as possible. Whether it be through protein skimmer, algae turf scrubbers, water changes, media removal, or macro algae you are still removing bio mass.

 

[Invic]

Tanks "crash" for numerous reasons. Old tank syndrome I believe started with the made up excuse for DSB failures. Basically a catchy phrase for the unknown or not wanting to assume their idea had a flaw.

As for eutrophic sorta failure that's just a loading issue. As well as the presence of an ATS doesn't mean it's functionally working as perceived.

As mentioned GFO is not without risks. Again a variable.

 

[Invic]

Lol back wife needed help mid post

Substrates don't matter unless you have certain livestock that needs sand. Otherwise it's just cosmetic. With sand you have to care for it and understand it fills up and needs emptied. No sand is just not dealing with sand maintence mostly.

To elborate on crashes, you can look at a tank setup and guess at a cause of a crash. But the more a reef keeper learns about what's really going on in a system the better you see past the generic it has x y z parts and can see the signs of changes with in a tank.

Each reefer will choose to learn or be happy with taking things at a face value of x y z. Both are fine. But sadly reefing based only on a basic view will never tell you why it failed.
Biology and chemistry run our tanks. Our interactions usually are basic at best. Our equipment is still kiddy stuff compared to what mother natures plans are.

To get a better understanding we have to constantly learn and explore. Mother Nature a vicious complex puzzle

 

[FlyPenFly]

Mother Nature a vicious complex puzzle

No kidding! LED vs MH/T5, Skimmers vs Skimmer-less, SSB vs DSB, Zeo vs feeders, etc... reef keeping seems like it was designed for internet fighting.

 

[Invic]

Haha ya, bright side is discussing debating and revisiting ideas and information can help find or realize new aspects to reefing.

Actually myself devoting a lot of time to algae research started out with a basic question. I forget the question I was after simply since I ran into a hundred more. Then I kept digging and digging to understand something I thought was far far simpler. Lol still reading about it and thinking.

Really that is a great thing in this hobby, you can learn a lot about the world around you while learning how to understand a bit more involved bio chemistry lol.

 

[Floyd R Turbo]

that pic is giving me a headache

 

[FlyPenFly]

Some interesting studies on the use of algae turf scrubbers for nutrient removal:

http://onlinelibrary.wiley.com/doi/10.1111/j.1526-100X.1993.tb00006.x/abstract

ATS use for phosphorous removal from eutrophic systems

http://www.sciencedirect.com/science/article/pii/027312239600354X

http://www.sciencedirect.com/science/article/pii/S0925857409003292

 

[Invic]

Well their all pay access, actually think I have one of those, I'll see if I can find it. It's the waste water one.

Those look to be all freshwater terrestial documents. Which exporting via algae is more capable. Phosphate levels in freshwater are insanely high. Which is why run off to the oceans is a huge environmental problem killing reefs.

As I was talking about before the freshwater levels being insanely higher the saturation of a cell is a lot higher. This allows a net reduction. Now the problem is as you lower from high eutrophic levels you get less and less per harvest. By the time you reach mesotrophic in freshwater water bodies (mid level basically) the algae is nearing starvation and can release nutrients. Combined with the lower nutrient yeild per cell you lose most all effectiveness.

While still those levels they are working in freshwater are vastly higher then even algae beds in the ocean where corals are long since dead.

My algae thread has a paper open link talking about having to remove the whole biomass of algae once it hits threshold. Without full removal not trimming levels will rebound. Again freshwater water.

 

[FutureDoc]

#1 and #2 both have Adey as authors... might as well be General Motors writing about the benefits of the Corvettes. Adey is an algae specialist and pioneer of the ATS system... his reef systems have been nothing but noted failures. I like his bio-fuel research but much of his algae nutrient control is not always up to par. Now, removing algae from an already eutrophic system is a good thing... but driving a system to a eutrophic state in order to grow algae as a mechism for export is not a good thing.

As with the Chesapeake Bay (I am a "Bay Native" as I spent every summer there basically sailing around the York River, Mobjack outflow and around Annapolis). The issue with the bay is NOT that we need to harvest algae, it is that we need better controls on the terrestrial pollutants. Just like our tanks, it is better if we manage thing before it becomes available to the algae rather than after it.

 

[Floyd R Turbo]

You guys keep going back to the argument of a eutrophic state. So an abundance of nutrients that support algal growth. But I don't have this. I am able to grow algae in a low nutrient state. One could argue that the low nutrient state is because of the algae. Indeed this is the basis of the scrubber. Throw out all the old Adey research. It doesn't directly apply as we're not talking waste water or fresh water, although many also run FW scrubbers and get results too.

I just don't believe you when you say that my scrubber is only working because I'm fostering a eutrophic state. It just doesn't make logical sense based on what I see happening.