Refugiums don't export nutrients?

[Reefin Dude]

I will take a shot at summing things up the way I see it... If a tank was to be meticulously maintained around the clock with hourly water changes, over-skimming and crew of siphoners on guard ready to suck out any trace of detritus then macroalgae could not survive in such a nutrient free environment. This environment would be ideal for growing SPS and many of the more delicate corals, but if macro was added into the system it would starve and release bad juju upon its death. A realistically maintained tank will have higher but varying nutrient levels that can usually support macros, but usually can not support the more delicate corals at the same time or for very long. Lots of people find a happy balance growing macros with hardier corals. There are always freak tanks that seem to defy science and have yet to be explained.

 

we would need to define delicate here. SPS are delicate because of the need for Pi free water. so, yes what you are saying is true. other species of coral may have other needs making them delicate. either a certain dietary need or other resources that are found in their particular patch of the reef. if algae was introduced into such a clean system, then yes it would starve and die, if it grows, then there is enough Pi there to support it.

 

there are a lot of micro environments and niches that organisms have adapted to. some have leeway others do not. which make reefkeeping more difficult, and why thinking that just because an organism came from warm SW does mean that it will survive in your warm SW.

 

G~

[Reefin Dude]

 

 

 

But it was just stated a few posts prior that bacteria can process all the DOC in a matter of hours, and since a skimmer is not perfect, there will still be a substantial net surplus of Pi. Are we now assuming that there is leftover Po that evades bacteria, and settles somewhere in the tank?

 

 

i think this is was your question in the your post, correct?

 

skimmers remove Po more than Pi. they are removing bacteria/other organics. they are not removing Pi directly. all of that detritus one sees is full of Po. some more easily converted to Pi than others. this is where creating a low O2 environment can come into play. the less O2 available for decomposition the slower the decomposition. this is of course also going on in substrates and yet another reason why some DSB's can be functional for many years. increasing the phosphates sink in the system. the skimmer/water column is another small phosphates cycle between available Pi bacteria, plankton. Pi is a valuable resource. something is going to use it. if a bacteria got it then it could very easily be removed by the skimmer the next time it goes through. Pi is always getting exchange. where that phosphorous atom is now may not be where it is an hour from now, and that hour from now it may be in a bacterium that can be skimmed off, stuck to calcium carbonate, or in an algae. the object is to have that phosphorous atom somewhere that can easily exported at least at some point.

 

G~

[xerophyte_nyc]

So the bottom line with everything written here, is that the mere ability to grow algae, by definition, precludes a low nutrient system - because if nutrients were indeed low, there wouldn't be algae. Therefore, utilizing the same said algae for nutrient export cannot effectively reverse the tank's course back to a low nutrient situation, because then there would be no algae to get you to that point.

[markalot]

So the bottom line with everything written here, is that the mere ability to grow algae, by definition, precludes a low nutrient system - because if nutrients were indeed low, there wouldn't be algae. Therefore, utilizing the same said algae for nutrient export cannot effectively reverse the tank's course back to a low nutrient situation, because then there would be no algae to get you to that point.

 

That's the way I understand it.

 

Algae growing is proof the nutrients are available for it to grow and stuff can bind some of it up before the algae can get to it. I should use Po vs Pi but I constantly get the two confused.

 

The real question for me is; supposing that is true, is it really worth the work involved to fix the issue? We can see 4 and 5 year old tanks surviving well, and as Geoff pointed out, there must be a phosphate sink of some sort. At least that is the theory, if everything else here is true. I'd rather have the sink than the work. Don't throw out the phosphate sink with the water ... something like that.

[FutureDoc]

So the bottom line with everything written here, is that the mere ability to grow algae, by definition, precludes a low nutrient system - because if nutrients were indeed low, there wouldn't be algae. Therefore, utilizing the same said algae for nutrient export cannot effectively reverse the tank's course back to a low nutrient situation, because then there would be no algae to get you to that point.

 

Yep, that sums it up well.

[markalot]

 

Doh! Another article that doesn't say anything that you claim!

 

 

Oh I don't know about that.

 

 

A portion of the phosphorus in the substrate may be reintroduced to the water column. Phosphorus stored in the uppermost layers of the bottom sediments of lakes and reservoirs is subject to bioturbation by benthic invertebrates and chemical transformations by water chemistry changes. For example, the reducing conditions of a hypolimnion often experienced during the summer months may stimulate the release of phosphorus from the benthos. Recycling of phosphorus often stimulates blooms of phytoplankton. Because of this phenomenon, a reduction in phosphorus loading may not be effective in reducing algal blooms for a number of years (Maki et al., 1983).

 

The important takaway for me is that the phosphate in the upper layers of the sediment can still be converted and re-introduced into the water column by the critters. This can continue to cause algae blooms even as phosphate is being actively reduced. Sediment = sandbed?

 

What is the contradiction?

[xerophyte_nyc]

That's the way I understand it.

 

Algae growing is proof the nutrients are available for it to grow and stuff can bind some of it up before the algae can get to it. I should use Po vs Pi but I constantly get the two confused.

 

Ok, let's take this a step further. No matter what, there will be some Pi. If we are practicing good husbandry and offering adequate food to our tank inhabitants, there will always be some Pi, we just need to try our best to intercept Po but some will inevitably become Pi.

 

With aggressive skimming you are also reducing some of the good DOC, which is the price to pay for reducing the initial input of Po, I suppose. Then periodic siphoning and WC helps with Pi. Shouldn't GFO or other method of Pi export still be used? After all, it won't be long (between WC and siphoning) until Pi in the water builds up again - unless there is an army of aquarium elves that are siphoning after every meal, like someone else pointed out earlier.

 

Does the "anti-fuge" camp not use any phosphate binding media?

 

Yep, that sums it up well.

 

It only took 280 posts

[FutureDoc]

Doh! Another article that doesn't say anything that you claim!

 

 

The magical game of cards and phantom phosphates that has never been studied and has no supporting document to back it up.

 

Seriously Reefin Dude and Mr. Doc, I'd almost believe you if this didn't seem like you were playing some game with paper cups and a little red ball. Either provide some documentation that proves you hypothesis, or stop repeating yourself over and over and linking to the same studies that don't say anything that you claim.

 

Let's talk facts.

"Phosphorus in freshwater and marine systems exists in either a particulate phase or a dissolved phase. Particulate matter includes living and dead plankton, precipitates of phosphorus, phosphorus adsorbed to particulates, and amorphous phosphorus. The dissolved phase includes inorganic phosphorus (generally in the soluble orthophosphate form), organic phosphorus excreted by organisms, and macromolecular colloidal phosphorus.

The organic and inorganic particulate and soluble forms of phosphorus undergo continuous transformations. The dissolved phosphorus (usually as orthophosphate) is assimilated by phytoplankton and altered to organic phosphorus. The phytoplankton are then ingested by detritivores or zooplankton. Over half of the organic phosphorus taken up by zooplankton is excreted as inorganic P. Continuing the cycle, the inorganic P is rapidly assimilated by phytoplankton (Smith, 1990; Holtan et al., 1988)."

 

How is this not supportive of my position? We have consistently shown peer-reviewed documentation of how P works within an aquatic environment.

 

Follow the arrows.

 

 

 

Go read "Lean and Nalewajko" as cited earlier. Learn what algae really does and get back. The hobby literature is mostly very weak and so the silver bullet you are looking for just is not there.

 

And I am Dr. MrDoc to you.

[markalot]

Ok, let's take this a step further. No matter what, there will be some Pi. If we are practicing good husbandry and offering adequate food to our tank inhabitants, there will always be some Pi, we just need to try our best to intercept Po but some will inevitably become Pi.

 

With aggressive skimming you are also reducing some of the good DOC, which is the price to pay for reducing the initial input of Po, I suppose. Then periodic siphoning and WC helps with Pi. Shouldn't GFO or other method of Pi export still be used? After all, it won't be long (between WC and siphoning) until Pi in the water builds up again - unless there is an army of aquarium elves that are siphoning after every meal, like someone else pointed out earlier.

 

Does the "anti-fuge" camp not use any phosphate binding media?

 

 

It only took 280 posts

 

No way man, I had this understood 4 months ago, but I still don't 100% agree.

 

They'll (and "they" don't all 100% agree but lets lump the poor bastards together ) have to tell you their stance on refugiums. Mine is that if anything, multiple methods almost always work better than just one. Unfortunately the claim here is the algae system hurts or makes low nutrients impossible, which really makes these discussions uncomfortable to deal with.

 

First introduce a different way to do it, then tell me I can't mix this way with other common methods. Do that and I will want to see a 5 year old tank proving to me this method works, and evidence on how forgiving this method is to periods of lax maintenance, accidents, etc.

 

It may be better, but is it better?

[FutureDoc]

Oh I don't know about that.

 

 

 

The important takaway for me is that the phosphate in the upper layers of the sediment can still be converted and re-introduced into the water column by the critters. This can continue to cause algae blooms even as phosphate is being actively reduced. Sediment = sandbed?

 

What is the contradiction?

 

 

A sandbed is a type of sediment but not all sediment are sandbed

 

Yes, but in out tanks, all of it is "upper layer" to a lesser extent. Great, now you are going to make me hunt down another article about sandbed and P concentrations in the atlantic.

 

Ok, let's take this a step further. No matter what, there will be some Pi. If we are practicing good husbandry and offering adequate food to our tank inhabitants, there will always be some Pi, we just need to try our best to intercept Po but some will inevitably become Pi.

 

With aggressive skimming you are also reducing some of the good DOC, which is the price to pay for reducing the initial input of Po, I suppose. Then periodic siphoning and WC helps with Pi. Shouldn't GFO or other method of Pi export still be used? After all, it won't be long (between WC and siphoning) until Pi in the water builds up again - unless there is an army of aquarium elves that are siphoning after every meal, like someone else pointed out earlier.

 

Does the "anti-fuge" camp not use any phosphate binding media?

 

 

It only took 280 posts

If there is some Pi, then we need to dilute... aka water change. New algae growth (like on the glass) will suggest that there is increasing Pi. Also, the use of GFO can help as well. I know G/Reefin Dude does not like it as much but I think small GFO reactors can help if used sparingly... you just do not want to rely on GFO to do the heavy P lifting. On the other hand, in my larger (40B) tank, I subscribe to a daily water change routine... small, only 1% (along with bi-weekly siphoning) but so far it was done wonders. Takes me all but 20 seconds to execute.

 

Only 280 post... it took me about 3-4 years to finally "get it" and it took me several months arguing with my grad-work adviser about it too boot.

 

 

I guess I'm still looking for the information about the magical phosphates that are expelled by algae.

 

Repeating information that doesn't say what you claim it says isn't helping your case. This is talking about plankton, not algae.

 

 

 

Read... what do you think phytoplankton is? I will give you a hint, a suspended chaeto-ball is, by definition, plankton.

 

If you have peer-reviewed evidence that says contrary to what we have been tanking about, please post and link to it. Getting to intellectual property is not a big deal.

 

---------------------------------------------------------------------------------------------------------

 

Markalot: Here is the article on sediment and P

 

 

http://www.faculty.virginia.edu/mcglathery/McG_Lab/Publications_files/McGlatheryEtal_Biogeochemistry1994Variable%20Rates%20of%20P%20Uptake...Mech%20and%20Ec%20Significance.pdf

 

Bluprt: You are in luck, another Prof likes open sources as much as I do... they have their "Source" online. Take a look

[xerophyte_nyc]

If corals need to be fed organically bound phosphates (which I think we all agree that they do), why would it matter if we can't test for organically bound phosphates in the water column? The phosphates that cause problems with corals are the phosphates that are inorganic that we can and do test for. You seem to be talking in circles about this mystery phosphate that has thus far eluded being tested or studied by anyone in the aquarium hobby.

 

Exactly. Po is good, and is consumed readily by coral and bacteria. So long as the ensuing Pi is exported, we still have ourselves a low nutrient environment. There are many ways to remove the Pi. Maybe algae isn't the best. Maybe the still un-quantifiable amount of Po algae contributes is a detriment. But at the end of the day, are we not still contributing to a low Pi system with a fuge/ algae/ ATS? No matter how hard we try there is still leftover Po that will become Pi. Our coral can still be happy even with plenty of Po.

 

The idea of rock and substrate becoming saturated needs to be addressed. Detritus can be siphoned, Pi can be liberated from the sand into the water column and then exported, but what about when the rock becomes full...

 

You can chase Po. You can chase Pi. It's a wild goose chase. Maybe focusing on elimination of Po (instead of Pi) is better in the long run because it can limit phosphate binding into substrates and rock?

[FutureDoc]

Interestingly, talking with Invic (see TRT), he puts algal Po excretion rates around 40-45% when there is a stable environment. 20% is about right for starvation/saturation events.

 

xero: Po is good... but our tanks are getting Po from our hands (feed), what we do not want is the tank to cycle it back while also feeding the tank. Po becomes Pi becomes Po becomes Pi... and so on. The issue is that as biomass increases, the whole process snowballs. Worse, each time there is a transaction, the P binding material (GFO, but worse Ca based material) takes a cut (like an ATM fee) and over time this is problematic. We remove the GFO when it is exhausted but removing the Ca can be difficult unless you plan for it. Mt <1inch sandbed is planned to be removed after a year of use.

 

Bluprt; You think that if you have chaeto, then we are not growing traditional unicellular phytoplankton just as well? You are getting bent our of shape using improper definitions... plankton is not all "zooplankton" eaten by whales, it is any pelagic organism that is unable to move against current... including jellyfish.

 

If you are going to put a rock on the chaeto, that kinda defeats the purpose because you will incite a mass algal die-off. I though chaeto had to be suspended and rotated to be effective... and who uses caulerpa as a export anymore?

[xerophyte_nyc]

If there is some Pi, then we need to dilute... aka water change.

 

Why would dilution be better than export via media? If someone wants to feed daily, it should be close to impossible to keep up with phosphates in a reef tank by doing water changes (within reason).

 

 

Also, the use of GFO can help as well. I know G/Reefin Dude does not like it as much but I think small GFO reactors can help if used sparingly... you just do not want to rely on GFO to do the heavy P lifting.

 

What binds Pi quicker: algae, GFO or unbound Ca?

 

 

On the other hand, in my larger (40B) tank, I subscribe to a daily water change routine... small, only 1% (along with bi-weekly siphoning) but so far it was done wonders. Takes me all but 20 seconds to execute.

 

1% water changes have done wonders in what way? That hardly seems like enough to make an impact on anything.

 

 

 

 

 

 

[FutureDoc]

Why would dilution be better than export via media? If someone wants to feed daily, it should be close to impossible to keep up with phosphates in a reef tank by doing water changes (within reason).

 

 

 

What binds Pi quicker: algae, GFO or unbound Ca?

 

 

 

1% water changes have done wonders in what way? That hardly seems like enough to make an impact on anything.

Ok part one: actually you are exporting with a water change, but you are diluting the total concentration. Sorry to confuse/swap terms. In out tanks, if low P is a goal, dilution reduction can be more important of the P concentration is 0.009 or less. On the other hand, a net loss of 1mg of P is more dependent on the volume it is leaving. So 1mg might be huge in one liter but irrevelent in 1 million liters. Sorry to swap terms.

 

Part two: Good question and it is kinda different on all fronts. Mostly, GFO and Ca need to be in proximity to a binding site... so however long it takes the P particle to read that point. Algae, it is kinda similar but with more variables as it depends on the ATP production of the algae cell as well as the proximity to the cell absorption. Generally speaking, Ca and GFO or Al Lant. will be faster as algae is not always producing ATP.

 

Edit: I want to put out one more thing. Actively growing algae cells and GFO really can become a P source. A growing group of algae will not re-release Po at a greater amount than it is consuming (just like a growing teenager will not likely release as much mass as it takes in). Ca can be a P source as well as dying algae cells. I think in certain more "extreme" conditions, GFO can release bound P but it is in really unique environments where pH, O2 and other things are playing funny games.

 

Three:Are you familiar with ORA'a consistently mediocre concept? In my system I would rather have very small export amounts from the system rather than allowing my system to have weeks of gradual increases between WC. I do not want algae/bacteria build up a biomass between days 7-14 after a WC and then go into survival mode days 1-7 (really it is faster than this but I use these timeframes as an example) I still siphon detritus with larger % WC every few weeks. I noticed that after I stopped carbon dosing (and the HA outbreak afterward) that I actually see carbon-like low-nutrient effects in my tank. After all, I feed daily, why not export some water daily. It also works well with keeping Ca/Alk non limiting for SPS. This is my personal husbandry method... and it is a way for me to cut down the WC... I was a bad 20-40%-er every few days... I have a WC problem

[Polarcollision]

Here's an interesting study showing growth rates of 9 different algae, testing limiting nutrient. Figure2: Control, phosphorus, nitrogen, and P+N for each. You can see that most did not grow well with nitrogen the limiting nutrient and phosphorus available. Codium edule was the biggest exception, growing well in a phosphorus enriched environment.

 

https://docs.google.com/viewer?a=v&q=cache:IbjfSohSRRIJ:web.mit.edu/qhorn/Public/Reef%2520Aquariums/Phosphorus%2520articles/Larned%2520Marine%2520Bio%2520132%25201998.pdf+what+percentage+of+macroalgae+is+phosphorus&hl=en&gl=us&pid=bl&srcid=ADGEESim3_3GdYFAeN2frKLKvirk-7qRonbpRg-uQcqTps3VRJaph75kEwgkai7S29ls5IOxU5Xs5OoP7hmeiJbmzRZb9pBCMvLmxtuGHzCNIUJH0QwBcKTsA_6CN9HpZA_pcGhEOfba&sig=AHIEtbRjtGBVR7I8PgohUAJDTgMW37m98w

 

Here's what Codium edule looks like: http://www.coralreefnetwork.com/marlife/stepath/images/codium_edule.jpg

[FutureDoc]

Here's an interesting study showing growth rates of 9 different algae, testing limiting nutrient. Figure2: Control, phosphorus, nitrogen, and P+N for each.

 

https://docs.google.com/viewer?a=v&q=cache:IbjfSohSRRIJ:web.mit.edu/qhorn/Public/Reef%2520Aquariums/Phosphorus%2520articles/Larned%2520Marine%2520Bio%2520132%25201998.pdf+what+percentage+of+macroalgae+is+phosphorus&hl=en&gl=us&pid=bl&srcid=ADGEESim3_3GdYFAeN2frKLKvirk-7qRonbpRg-uQcqTps3VRJaph75kEwgkai7S29ls5IOxU5Xs5OoP7hmeiJbmzRZb9pBCMvLmxtuGHzCNIUJH0QwBcKTsA_6CN9HpZA_pcGhEOfba&sig=AHIEtbRjtGBVR7I8PgohUAJDTgMW37m98w

Looks like a good one.

[d0lph1n]

These guys have good arguments and examples pro refugiums:

http://www.triton.de/cms/upload/Triton_PDF_T-Methode_EN.pdf

[FutureDoc]

Seriously? If your P concentration is .009, then removing 1% of the water removes .00009 ppm of your phosphates and you are left with a tank that has .00891 ppm of phosphates. Your phosphates will return to their previous level if one spore of pollen drops into your tank.

 

Perhaps you don't understand percentages. 1% is 1% if you are talking about 1 liter, or 1 MILLION liters. It's still just 1%

 

Really, re-read what I posted. We can wait for you to catch up. I will bold it it help.

 

Ok part one: actually you are exporting with a water change, but you are diluting the total concentration. Sorry to confuse/swap terms. In out tanks, if low P is a goal, dilution reduction can be more important of the P concentration is 0.009 or less. On the other hand, a net loss of 1mg of P is more dependent on the volume it is leaving. So 1mg might be huge in one liter but irrevelent in 1 million liters. Sorry to swap terms.

 

Where did I say 1%? I was talking about mass and parts per million. Considering the conversions between net mass and PPM is very important.

[FutureDoc]

d0lp1n: Did not see/hear when they were talking (and I could understand) what minute were they speaking (I kinda bounced the player back and forth trying to find it)

 

Polar: Nitrogen does have an effect on limiting algae, especially on the reef and it depends on the location as well. In some zones, Iron is limiting. Anyway, our tanks have an ability to exercise nitrogen from the tank even without DSB or coil Denitrators, our tanks have a harder time with phosphate. Still, that is a good fine, definitely keeping that one. Notice how algae became dependent on sediment and flow... very interesting. Either it had to be near bacteria or had to be in a area where the volume was providing a lot of passing P particles over time. Kinda like our powerheads and overflows.

[xerophyte_nyc]

Po is good... but our tanks are getting Po from our hands (feed), what we do not want is the tank to cycle it back while also feeding the tank. Po becomes Pi becomes Po becomes Pi... and so on.

Po input--> Pi, but some/ most of that binds algae/ media --> leftover Pi + some leaky algae Po --> bacteria makes more Pi --> more algae uptake, binding to Ca...but the P gets smaller and smaller with each step as long as it is correctly and regularly exported. It is not a snowball effect unless maintenance stops.

 

At some point substrate becomes saturated and can no longer adsorb more P, so just replace some substrate with a new batch periodically. Or use more media to take care of the now greater amount of P in solution. Or don't use a calcium based substrate.

 

If the sandbed is good at adsorbing P, why don't we see nuisance algae that often on the sandbed? Cyano, yes...but why no macro?

 

[FutureDoc]

Po input--> Pi, but some/ most of that binds algae/ media --> leftover Pi + some leaky algae Po --> bacteria makes more Pi --> more algae uptake, binding to Ca...but the P gets smaller and smaller with each step as long as it is correctly and regularly exported. It is not a snowball effect unless maintenance stops.

 

At some point substrate becomes saturated and can no longer adsorb more P, so just replace some substrate with a new batch periodically. Or use more media to take care of the now greater amount of P in solution. Or don't use a calcium based substrate.

 

If the sandbed is good at adsorbing P, why don't we see nuisance algae that often on the sandbed? Cyano, yes...but why no macro?

 

Yes, but lets take that out to daily feeding. We have daily feeding and yet, not all of it makes it to the algae for removal. So we are looking at a slow overall increase (eutrophication).

 

Not use substrate: that is the BB folk's method. It work too. You still have to deal with the rocks but they bio-turbate and detritus will work its way down to the tank's sandless bottom.

 

Cyano does out compete macro in the sandbed. You do see phytoplankton and benthic film algae on the substrate as well. Why did you think that a lot of folks put a sandbed under their chaetoball in the sump?

 

 

Only one species, Codium edule, was found to have reduced growth rates due to phosphate limitations. The remaining 8 species had reduced growth rates from nitrate limitations.

 

I guess macroalgae can grow in systems that have ultra low phosphates after all.

 

 

See your post above where you said 1% water changes were a great way to remove phosphates. Short term memory?

 

It is all about the limiting nutrient (see Liebig's law of the minimum). In out tanks N is easier to prevent large amount but it more difficult to be limited. Algae is easier to be limited by out efforts with P. Also, keep in mind that algae can fix N but can fix free-P.

[Polarcollision]

FutureDoc: I realize that about Nitrogen (and Fe) especially since Caulerpa growth reversed when phosphates were available and nitrogen was limiting; just posted the phosphorus bit since that seemed more relavent to the topic. I personally would grow Codium edule if my goal was exporting phosphorus.

 

Someone asked about what to do when substrate becomes saturated with P: Read a study about pH ~8.4 stabilizing the crystal its bound in so that it doesn't release back into the water column. Sorry no reference bookmarked... hopefully Google can scare it up.

[FutureDoc]

Bluprt: I started talking about my 1% on post 286 and it is part of my husbandry method (nothing deleted). You can see a full discussion on TRT about it. It is part of my daily export along with frequent detritus siphoning and aggressive skimming. I have no idea where you missed the train on that discussion

 

Polar: yeah, I completely get it.

 

Another not of reference for polar's article was that N was more limiting in the water column than P out on the reef and that algae if it was near the sediment with a P source would survive in an otherwise poor P water column. I might need to read to see where their samles were taken, but it is important to remember that our tanks are always within a few feed of the "sediment". So it kinda distorts the concept. Again, an important thing to distinguish that P limitations in the water column are secondary to P within the system.

[Reefin Dude]

But it was just stated a few posts prior that bacteria can process all the DOC in a matter of hours, and since a skimmer is not perfect, there will still be a substantial net surplus of Pi. Are we now assuming that there is leftover Po that evades bacteria, and settles somewhere in the tank?

 

yes. either settle it somewhere where the decomposition is kept to a minimum, or let the bacteria use it, then remove the bacterium using the skimmer. how carbon dosing works. using the phosphate cycle with bacteria in the water column itself.

 

So the bottom line with everything written here, is that the mere ability to grow algae, by definition, precludes a low nutrient system - because if nutrients were indeed low, there wouldn't be algae. Therefore, utilizing the same said algae for nutrient export cannot effectively reverse the tank's course back to a low nutrient situation, because then there would be no algae to get you to that point.

 

Bingo.

 

That's the way I understand it.

 

Algae growing is proof the nutrients are available for it to grow and stuff can bind some of it up before the algae can get to it. I should use Po vs Pi but I constantly get the two confused.

 

The real question for me is; supposing that is true, is it really worth the work involved to fix the issue? We can see 4 and 5 year old tanks surviving well, and as Geoff pointed out, there must be a phosphate sink of some sort. At least that is the theory, if everything else here is true. I'd rather have the sink than the work. Don't throw out the phosphate sink with the water ... something like that.

 

that is up to the aquarist. do you want to do a little work all of the time, or do a lot of work every now and then. Paul's tank is a great example on one end, and Jerel's/mine was on the other. it is all about putting phosphates in the phosphate bank (sink), and how big of a bank you want to have. how much poo do you want to keep as a pet. the bottom line is that the wastes have to be removed and algae growing is an indicator that the system is not oligotrophic. if that matters to the environment that is trying to be emulated.

 

Exactly. Po is good, and is consumed readily by coral and bacteria. So long as the ensuing Pi is exported, we still have ourselves a low nutrient environment. There are many ways to remove the Pi. Maybe algae isn't the best. Maybe the still un-quantifiable amount of Po algae contributes is a detriment. But at the end of the day, are we not still contributing to a low Pi system with a fuge/ algae/ ATS? No matter how hard we try there is still leftover Po that will become Pi. Our coral can still be happy even with plenty of Po.

 

The idea of rock and substrate becoming saturated needs to be addressed. Detritus can be siphoned, Pi can be liberated from the sand into the water column and then exported, but what about when the rock becomes full...

 

You can chase Po. You can chase Pi. It's a wild goose chase. Maybe focusing on elimination of Po (instead of Pi) is better in the long run because it can limit phosphate binding into substrates and rock?

 

correct. eliminate the source of the Pi. remove the detritus if it is large enough. if small enough have a properly sized skimmer that can process a good amount of the water every hour. LR luckily does purge itself if good flow is around it, but turkeybasting every now and then is never a bad thing either. the bacterial migration channels need to kept open in order for the process to be ongoing.

 

Here's an interesting study showing growth rates of 9 different algae, testing limiting nutrient. Figure2: Control, phosphorus, nitrogen, and P+N for each. You can see that most did not grow well with nitrogen the limiting nutrient and phosphorus available. Codium edule was the biggest exception, growing well in a phosphorus enriched environment.

 

https://docs.google.com/viewer?a=v&q=cache:IbjfSohSRRIJ:web.mit.edu/qhorn/Public/Reef%2520Aquariums/Phosphorus%2520articles/Larned%2520Marine%2520Bio%2520132%25201998.pdf+what+percentage+of+macroalgae+is+phosphorus&hl=en&gl=us&pid=bl&srcid=ADGEESim3_3GdYFAeN2frKLKvirk-7qRonbpRg-uQcqTps3VRJaph75kEwgkai7S29ls5IOxU5Xs5OoP7hmeiJbmzRZb9pBCMvLmxtuGHzCNIUJH0QwBcKTsA_6CN9HpZA_pcGhEOfba&sig=AHIEtbRjtGBVR7I8PgohUAJDTgMW37m98w

 

Here's what Codium edule looks like: http://www.coralreefnetwork.com/marlife/stepath/images/codium_edule.jpg

 

what FD says below.

 

d0lp1n: Did not see/hear when they were talking (and I could understand) what minute were they speaking (I kinda bounced the player back and forth trying to find it)

 

Polar: Nitrogen does have an effect on limiting algae, especially on the reef and it depends on the location as well. In some zones, Iron is limiting. Anyway, our tanks have an ability to exercise nitrogen from the tank even without DSB or coil Denitrators, our tanks have a harder time with phosphate. Still, that is a good fine, definitely keeping that one. Notice how algae became dependent on sediment and flow... very interesting. Either it had to be near bacteria or had to be in a area where the volume was providing a lot of passing P particles over time. Kinda like our powerheads and overflows.

 

here we get into knowing what is limiting for an organism to live in our case here we are talking algae. some cases it is Fe, some it C, some it is Pi, some it is nitrate, and even CO2. those with planted FW tanks know this. it is the same for our systems. the algae limit for nitrate is 0.1ppm. again our test kits are not up to the task.

 

Po input--> Pi, but some/ most of that binds algae/ media --> leftover Pi + some leaky algae Po --> bacteria makes more Pi --> more algae uptake, binding to Ca...but the P gets smaller and smaller with each step as long as it is correctly and regularly exported. It is not a snowball effect unless maintenance stops.

 

At some point substrate becomes saturated and can no longer adsorb more P, so just replace some substrate with a new batch periodically. Or use more media to take care of the now greater amount of P in solution. Or don't use a calcium based substrate.

 

If the sandbed is good at adsorbing P, why don't we see nuisance algae that often on the sandbed? Cyano, yes...but why no macro?

 

if the flow is great enough, than cyano can not get a foothold, it keeps getting blown away. if the flow is high enough, then the Pi released from bacteria action at the top of the substrate is moved away, adding Pi to the water column. the phosphate levels in the substrate have to get really bad before algae can get a hold of in the substrate and start growing. another good indicator that the substrate is in need of refreshing or replacement.

 

have you notice people with substrates start using more and more GFO and other after the fact phosphates binders as the system matures in order to try and keep up with the substrates release of Pi from bacterial action. another good indicator that the system is reaching saturation is low alk only. all of the bacteria stripping the elemental carbon out of the water column. ever wonder why "reef specific" salts are so high in alk and Ca? it is not because of coral growth it is fighting the affects of all of that bacteria working on wastes.

 

G~

[d0lph1n]

d0lp1n: Did not see/hear when they were talking (and I could understand) what minute were they speaking (I kinda bounced the player back and forth trying to find it)

 

I said examples and I provided a pdf. Have you checked the pdf? i'm out of this topic so don't expect any more replies form me.