Shower thoughts on phosphate

[victoly]

Because I don't have enough to think about, while showering i thought about phosphate. We as reef keepers regularly struggle with phosphate. We struggle to measure it accurately, and even when we do (we don't), what does it mean?

I postulate that we can only get dissolved phosphate readings in a very small range of the overall spectrum of phosphate. I've made an illustration.

I believe that every tank will have a different threshold of excess PO4 which will cause algae growth to take off. This number is affected by the coral uptake, source water input, nutrient removal methods and probably 100 other variables that are above my pay grade. Once you hit that threshold, algae growth starts and drops PO4. Any readings taken over that threshold will have a low bias. HOWEVER, this isn't a static calculation. Dissolved PO4 is a differential equation where both your inputs AND outputs are variable and interdependent. What am I getting at here? Honestly, I have no idea. It was just a shower thought.

[Sascha D.]

Love the chart!

A complicated issue for sure. I'm guess this is in reference to organic phosphates only? Of course I totally agree. I often see people with hair algae problems discounting phosphates because they read low, but they wouldn't have hair algae without phosphates. Nature makes out lives tough!

[Timfish]

Sounds good. But as far as I know our test kits are testing inorganic or orthophosphate and not organic phosphate which may account for the apparent discrepancy. As you point out every tank is different and beside not being able to test for every form of phosphate (and are there forms that might show up on a test kit but not be "bioavailable"?) what maybe more important long term is what microbial species are present and what are they doing with phosphate but agian that's not something we can easily test for.

Another question is what happens if no remediation is done. In my experiences most nuisance algae problems follow the chart Nilsen and Fossa give for the maturation of a tank (The Modern Coral Reef Aquarium, Vol I pg 164). During the 8 - 12 months the various nuisance alga go through cycles lasting from a few weeks to several months. What I've seen in my tanks over the years is 80% to 90% percent of the nuisance algae problems will pretty much follow their chart. Any action on my part is just mechanical removal for aesthetics, maybe a few brief minutes with a toothbrush or syphoning when I do a water change.

One experience I had was with a system I maintain in a house that was vacant for over 3 years. The system is built in and has access from a utility room that opens onto the patio and between workers and realitors (I want to be very specific I'm not referring to JeeperTy) leaving the door open to the elements and an electrician turning the electricity off for days to wire a new addition (tank had it's own circuit! ) the system was crashed multiple times. Outside of replacing a few yellow tangs and clown the owners never let me spend the time or money remediate the system so alga problems were rampant every time. What opened my eyes was just with small weekly water changes in roughly 2-4 months the algae would cycle through and disappear.

While I was initially pretty consistent testing water as many aquarists do I started relying more and more on the old eyeball tester and not on my test kits. Seeing corals consistently growing and being removed I assumed water parameters were fine. I was very surprised when on my oldest system then when I tested it I had phosphate, P04, at over 3 ppm. (At this point I want to emphasize I do not advocate keeping high phosphates! Many may label me hypocritical but if anyone asks I will say they need to keep PO4 around .1 ppm.) But keeping this system:

with P04 at levels 20 times higher or more than is recommended for well over a decade I gotta think it's those "other variables" that are what's critical for nuisance alga control.

For the most part the corals in my tanks I've been growing since the mid 90s so a fair criticism is I've just adapted some variants to tolerate high phosphates. This system here:

is the first system in which I kept a significant percentage of so called "SPS". Again I ended up using mostly the eyeball tester but since it was running a refugium with mud I did test P04 very occasionally and was impressed it took over 4 years for P04 to get between .34 - .43 mg/l (Elos). Unfortunately this system was dissmantelled a year and half ago but since then I've been playing with some seratiopora's and acropora's in some of my other tanks and so far I'm surprised, so far, to see them as tolerant as my other corals.

A significant event that happened in the 4th year with this system was one of the timers failed and left 2 of the 7 MH fixtures on for 3 or 4 days before it was caught. Several of the corals partially bleached, particularly the two green slimers had a notable reduction in the intensity of their green coloration. What I observed with this event was a breakout of cyano and the brwon diatoms so common on sand with new setups. Fortunately it only took a couple of weeks for the corals to regain their coloration then with in a few more weeks the cyano and diatoms cleared up. Looking at the research showing corals will pull nutrients out of the water when they can not get enough plankton to feed their zooxanthellae and when the amount of nutrients removed is moderated by the number of symbionts the sequence that makes sense is the corals had a stress event that in response they reduced their nutrient uptake, this then left ammonia, nitrates and phosphates available for the nuisance alga to grow, as the corals recovered their demand for ammonia, nitrate and phosphate returned to normal. Had I aggressively persued phosphate removal when the nuisance alga showed up I very well could have slowed down the acros recovery and may have actually caused the problem to escalate since we know phosphate is needed by the corals to utilize nitrates.

Here's a couple of refferences with more to follow when I figure out how to keep the links from dissappearing when I preview the post.

http://jeb.biologists.org/content/214/16/2749.full High phosphate requirements

http://link.springer.com/article/10.1007/s00338-003-0312-7#page-1 Effect of feeding natural zooplankton on skeletal growth

[FarmerTy]

That's beautiful. I have been running this over and over in my head as well the last couple of months as my phosphates kept testing at 0 ppb. I was coming to the conclusion as well that although it's nice to be able to measure the unbound, inorganic phosphate in our tanks, what does that number really mean? I actually started to ignore the reading and just judge from my SPS coloration and the amount of algal growth in the tank.

Your graph illustrates it perfectly. If you read a low phosphate concentration, you're either in the area where algal growth is interfering with your readings causing a low reading... or you are in the area where there is minimal algal growth and you just have low phosphates. One scenario, the algae is uptaking the phosphate and skewing your phosphate number low... the other way, your unbound phosphate level is just low.

So perhaps we should go with the caveat of:

A) Is your phosphate concentration low?

B) If yes, is there noticeable algal growth in your tank? Or do you often clean your glass due to algal film?

C) If yes, you have higher phosphates than your test is telling you... employ a form of removal (water changes, GFO, lanthanum chloride, etc.)

Same scenario:

A) Is your phosphate concentration low?

B) If yes, is there noticeable algal growth in your tank? Or do you often clean your glass due to algal film?

C) If no, you have minimal algal interference in your phosphate reading and it is probably correct.

D) Keep doing what you are doing. :-)

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[FarmerTy]

Wuh? Tapatalk turned my b) into smiley faces! Way to upstage my critical thinking!

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[jolt]

So how do you factor coral coloration into the decision tree?

Background: I have been reading 0 phosphates for several months, so turned off GFO. Recently started getting quite a bit of hair algae. Acros and some montis became essentially brown. At first I thought the coloration was due to low lights so started cranking lights up slowly over time but only saw increased algae growth and beginnings of bleaching. Started using GFO again, scrubbed off/siphoned out algae, and lowered light intensity. Now waiting to see what happens. I've sort of come to the conclusion that it I had too high phosphates even though I was not measuring any. Now I'm waiting to see if algae reappears and also what will happen with coral coloration.

[FarmerTy]

Tim, your longer-term experience is definitely beneficial for us to understand the role of phosphates in our systems.

I too, employed a higher nutrient environment to nurture my corals (mainly SPS) back to health during my upgrade. I think I went on a rant about this somewhere on the club but I stopped running GFO, biopellets, and stopped skimming so that nutrient levels would climb in my tank. The hope was for the direct uptake of nutrients from the water for nitrates and phosphates by the coral... I even dozed amino acids heavily during this time period. The goal was to nurse them back to health since they were teetering on death. The elevated nitrate levels browned out my acros and I'm sure the higher phosphate inhibited some of the precipitation of calcium slowing SPS growth. The benefit though was healthy, recovering SPS colonies and frags. They weren't pretty, but they were getting healthier.

I mentioned this before but at least for SPS, we skirt the line of making them look the prettiest they can be at some cost to their health. The higher nitrate levels increase the zooxanthallae within the coral allowing them the ability to feed their host more... but all we see is a brown stick since zooxanthallae will reflect a brown pigmentation. Healthy, but, uuuggllllyyy! Then we lower nutrients and slam them with light, they dump all their zooxanthallae and the brilliant color we see is actually their defense to being bombarded with light and the loss of brown zooxanthallae. It's pretty, but probably not as healthy as that brown stick. Zeo, carbon dosing, Triton, balling method, they are all loosely based on the principle of removing the nutrients (starving the coral, controlling nutrients), and then adding back nutrients for the corals to uptake. In the end, we all do the dance of some nutrients, but not too much, to keep great looking corals in our tanks.

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[FarmerTy]

So how do you factor coral coloration into the decision tree?

Background: I have been reading 0 phosphates for several months, so turned off GFO. Recently started getting quite a bit of hair algae. Acros and some montis became essentially brown. At first I thought the coloration was due to low lights so started cranking lights up slowly over time but only saw increased algae growth and beginnings of bleaching. Started using GFO again, scrubbed off/siphoned out algae, and lowered light intensity. Now waiting to see what happens. I've sort of come to the conclusion that it I had too high phosphates even though I was not measuring any. Now I'm waiting to see if algae reappears and also what will happen with coral coloration.

Jim, I would revisit my earlier post, if phosphate concentration is low... is there algae... etc.

For coloration of SPS corals in particular, it's really just a dance with removing enough phosphates, but not too much. I've always noticed a peak coloration around 0.03 ppm in SPS. Any lower and I started getting faded colors. Any higher and things started to brown out a bit. I think once you saw the 0 ppm of phosphate, you assumed it was too low in your tank overall but you probably had algal interference. Once you stopped using GFO, the algae kept uptaking the phosphate as the level increased and though you saw no increase in the actual concentration of phosphate, your levels did increase, but the algae was uptaking it.

I would just continue to use GFO until the algae recedes, and then base things purely on your visual observation of color for your SPS. When your Hawkins echinata goes from a drab blue to this sparkling iridescent, almost pearly blue, you know you're at a good concentration of phosphate. I almost stopped using my Hanna meter entirely once my corals had really good color because I could really base it off coloration alone. From that point, I ideally found the perfect schedule of GFO replacement (i.e., 1.5 cups every month) and stuck to that and my colors never waivered. Hope that helps!

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[victoly]

Tim I wonder if your success with higher phosphate systems has to do with the fact that they're being removed biologically as opposed to removal by dilution or GFO. I can't work out why that would be exactly. But maybe because the biological demand is constant and/or increasing? As opposed to GFO where you have a constantly declining utility rate until the media is exhausted at which point you introduce a much greater rate of removal? Maybe its the cycling/timing that gives those of us on the luddite side of the scale algae issues.

[victoly]

So how do you factor coral coloration into the decision tree?

Background: I have been reading 0 phosphates for several months, so turned off GFO. Recently started getting quite a bit of hair algae. Acros and some montis became essentially brown. At first I thought the coloration was due to low lights so started cranking lights up slowly over time but only saw increased algae growth and beginnings of bleaching. Started using GFO again, scrubbed off/siphoned out algae, and lowered light intensity. Now waiting to see what happens. I've sort of come to the conclusion that it I had too high phosphates even though I was not measuring any. Now I'm waiting to see if algae reappears and also what will happen with coral coloration.

Jim, I would revisit my earlier post, if phosphate concentration is low... is there algae... etc.

For coloration of SPS corals in particular, it's really just a dance with removing enough phosphates, but not too much. I've always noticed a peak coloration around 0.03 ppm in SPS. Any lower and I started getting faded colors. Any higher and things started to brown out a bit. I think once you saw the 0 ppm of phosphate, you assumed it was too low in your tank overall but you probably had algal interference. Once you stopped using GFO, the algae kept uptaking the phosphate as the level increased and though you saw no increase in the actual concentration of phosphate, your levels did increase, but the algae was uptaking it.

I would just continue to use GFO until the algae recedes, and then base things purely on your visual observation of color for your SPS. When your Hawkins echinata goes from a drab blue to this sparkling iridescent, almost pearly blue, you know you're at a good concentration of phosphate. I almost stopped using my Hanna meter entirely once my corals had really good color because I could really base it off coloration alone. From that point, I ideally found the perfect schedule of GFO replacement (i.e., 1.5 cups every month) and stuck to that and my colors never waivered. Hope that helps!

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The hawkins in the coal mine!

[victoly]

Tim, your longer-term experience is definitely beneficial for us to understand the role of phosphates in our systems.

I too, employed a higher nutrient environment to nurture my corals (mainly SPS) back to health during my upgrade. I think I went on a rant about this somewhere on the club but I stopped running GFO, biopellets, and stopped skimming so that nutrient levels would climb in my tank. The hope was for the direct uptake of nutrients from the water for nitrates and phosphates by the coral... I even dozed amino acids heavily during this time period. The goal was to nurse them back to health since they were teetering on death. The elevated nitrate levels browned out my acros and I'm sure the higher phosphate inhibited some of the precipitation of calcium slowing SPS growth. The benefit though was healthy, recovering SPS colonies and frags. They weren't pretty, but they were getting healthier.

I mentioned this before but at least for SPS, we skirt the line of making them look the prettiest they can be at some cost to their health. The higher nitrate levels increase the zooxanthallae within the coral allowing them the ability to feed their host more... but all we see is a brown stick since zooxanthallae will reflect a brown pigmentation. Healthy, but, uuuggllllyyy! Then we lower nutrients and slam them with light, they dump all their zooxanthallae and the brilliant color we see is actually their defense to being bombarded with light and the loss of brown zooxanthallae. It's pretty, but probably not as healthy as that brown stick. Zeo, carbon dosing, Triton, balling method, they are all loosely based on the principle of removing the nutrients (starving the coral, controlling nutrients), and then adding back nutrients for the corals to uptake. In the end, we all do the dance of some nutrients, but not too much, to keep great looking corals in our tanks.

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Triton is a huckster IMO. I saw him have it out with a guy who is a UT PHD coral geochemist who in no uncertain terms told him that it would take a technological revolution to get the accuracy that the triton lab manager claimed to get, irrespective of the 40 dollar price tag.

[+brian.srock]

While I was doing some tank maintenance the other day I had the idea to switch to a 2 in 1 shampoo which should shave off a minute while in the shower. I also think the wife was washing the shower mat since when I stepped out I caused a puddle so I need to find that mat.

[FarmerTy]

I'm curious about the ability for them to read the concentrations accurately. I'm not so much interested in the Triton method, more so curious about the levels in the tank.

Curiosity may just prompt me to submit a water sample just to see what I get back.

[victoly]

It's very unlikely that they can. Like I said, a guy who literally runs very accurate lab equipment SPECIFICALLY designed to do what Triton does for a living, who has studied coral for a decade and makes his living analyzing aqueous geochemistry and coral skeletons said that it wasn't possible using current technology. I'll believe the academic over the guy trying to sell you something 100 times out of 100.

[FarmerTy]

That my friend, I tend to agree with you on.

Surely though he can get some of the basics correct (Ca, Mg, Fe, Cu), at least the one's that us hobbiest have hobbiest-grade test kits for currently.

You have a link to their "discussion"? I want to read up on it a bit more.

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[victoly]

I was actually just trying to find it. It was a fb conversation with several reef chemistry heavy hitters. The first thing that tipped me off that triton guy was a snake oil salesman was that there would be NO impact to a nitrate sample shipped at room temp. to europe. C'mon. I can BARELY get nitrate accurately measured overnight shipping, on ice, from 200 miles away. The question then becomes what level of accuracy is acceptable, but still. This guy seemed more amped to sell than he was to explain how he achieved amazing results.

[FarmerTy]

Haha, I thought the same thing about nitrates. I always remembered having to rush any groundwater samples that had nitrate as an analyte and have the lab analyze immediately upon receipt.

[Bpb]

With as many corals you see in tims tank videos I have no doubt that the corals themselves are both adapted to live in high phosphate environments, AND are removing it biologically. Plus...I see almost no bare rock in that tank. If not on the glass, algae will have nowhere to even grow anyway. My corals typically kill algae all on their own as they spread.

[Reburn]

To the best of my knowledge the Triton test will not be testing for alk, ammonia, nitrates or nitrites.

They will test for following Parameters with ICP-OES :

Na, Ca, Mg, K, Sr, B, Br, S,

Li, Be, Ba, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Al, Si, As, Sb, Sn, Cd, Se, Mo, Hg, P (PO4), Pb, I

I purchased some testing through them. 4 samples to be exact which I plan on testing quarterly.. Now I am not buying into the Triton method nor do I have any plans to dose their "special" minerals. I am interested in the water chemistry aspect of it and to see what they come up with. However I feel that many of these minerals have a limited impact on coral growth, especially the heavy metals. I also feel that with regular water changes the majority of these elements that would be depleted are replenished. My interest is more on the depletion of these elements in running a tank without water changes. Now with all that being said I am in the no water change camp unless I have to. I allow my p04 and nitrate levels to dictate when I have to do water changes. I monitor these levels with my testing regiment and my eyeballs like most everyone on here.

I also just don't know about the p04 levels and how they correspond to what is bioavailabile with regards to organic and inorganic p04.

I do know about animal health though, and I do know that there is a science behind chealating minerals so they can be available for uptake by the animal. There has been many documented reports written about non chelated minerals vs chelated minerals and their uptake into livestock written by TAMU and the like. We are leaps and bonds ahead in animal husbandry vs coral husbandry and I just don't believe 100% that dumping "elements" into your tank corresponds to them being available to the coral. There are too many factors that can cause elements to bind to each other and organic compounds and precipitate out and that I feel we don't fully understand yet. But these reactions happening can skew test results as showing what is actually there therefor giving the perception that these elements are being "used".

[Timfish]

More references to waste time reading:

Uptake of inorganic posphorus and nitrate negatively effected by temp & pH changes
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0025024

Uptake, retention and release of ammonium of reef corals
http://aslo.org/lo/toc/vol_23/issue_4/0725.pdf

Ammonium uptake of symbiotic and aposymbiotic corals
http://www.ingentaconnect.com/content/umrsmas/bullmar/1979/00000029/00000004/art00011

Nitrate uptake
http://wap.aslo.org/lo/toc/vol_48/issue_6/2266.pdf

Too much zooxanthellae is bad (corals can be obese)
http://www.sciencedaily.com/releases/2012/10/121014162914.htm

Nutrient uptake by A. palmata at natural concentrations
http://www.aoml.noaa.gov/general/lib/CREWS/Cleo/St.%20Croix/salt_river47.pdf

These last two are very fascinating in that they reveal a coral colony's experiences influence it's response to changes in it's environment and bleaching is not simply caused by meeting a predetermined threshold.
http://www.mendeley.com/catalog/experience-shapes-susceptibility-reef-coral-bleaching/

http://www.plosone.org/article/info:doi/10.1371/journal.pone.0034418

[Timfish]

. . . For coloration of SPS corals in particular, it's really just a dance with removing enough phosphates, but not too much. . .

So where's too much or just enough? This M. digitata is one of my experiments, P04 is >2.0 mg/l

PO4 in he tank this Birdsnest is in was greater than 2.00 mg/l at the time this photo was taken, it's also about 3 years growth from a roughly 2" frag.

Since the photo P04 has dropped to less than .4 without any GFO. Tap water is used for water changes and last time I checked it P04 was .2 mg/l

[FarmerTy]

I'll be honest Tim, most of my observations are based on acropora and not birdsnest or digis. I always had good color on those so there wasn't much need to observe them to tweak for colors. They always seemed to show great color for me in any condition.

For the acropora, I noticed subtle coloration around 0.1 ppm (instead of just a brown or brown with green highlights stick) and anything below 0.05 ppm showed most of the natural colors. At 0.03 ppm, is where I saw the best coloration and as I crept lower than that, my acros started showing the dreaded "pastel" color... a very faded, pale version of the coral.

[Timfish]

Ty, I have to thank you for providing an excellent opportunity for me to get on one of my soap boxes and rant! :-D I'll say nice things about you the rest of the day! Just looking at a few species of Acropora shows how misleading it is to use the term "SPS" when talking about corals. I know for the most part we do not know the exact species we are dealing with but I feel as as best as possible we need to be specific not only to the species level but to the variant or conditions needed for specific colors when a species has a range of colors potentially available. (I have lamented before the need for a communal database.)

My experiences with Acropora youngei, A. millipora and A. valide is their colors are only influenced by light intensity. Attached is a picture of A. valide from the same tank with A. youngei, "Green Slimmer", from my first post on this thread with PO4 between .34 and .41. I regret not having any clear picturtes but the A. millipora varied from a nice green around 200 PAR to a pleasing peach and yellow around 500 PAR. This is what I would expect looking at their species description in Veron's "Corals of Australia and the Indo-Pacific" (printed in 1992 by university of Hawai'i this book is still an excellent buy at about $80). These species are found in multiple reef communities indicating adaptable species providing lighting is bright enough (Veron gives broad descriptions for 14 different community types for tropical reefs for hermetic coral communities, Delbeek and Sprung detail 11 basic zones in Vol I of their Reef Aquarium seiries). Looking at your Acropora echinata it is only found in deep, clear water strongly suggesting a species needing very specific requirements to do well. It shouldn't be surprising at all that it would be a good indicator species for a specific set of environmental conditions. But considering the range of environmental conditions Acroporas grow in I certainly would not expect every species to like the same conditions. A final point, with some acropora species though, coloration may be primarily influenced by water flow and not light intensity/spectrum or nutrient levels, an excellent example is this thread:

http://www.austinreefclub.com/topic/24657-color-and-growth-influenced-by-water-flow/?hl=%2Btwo+%2Btone

I do not have an answer as to why high phosphates do not cause algae problems in my systems as would be expected. I do know I've been able to duplicate it. I'm also very comfortable speculating it has to do with systems maturing that may develop biological controls. One reason I suspect this is long ago when I recognized a system that was doing better than average I would use water from it to seed other systems, in some cases I saw dramatic results. Admittidly in others no difference at all but that a 10% water change with "dirty" water would sometimes have good results suggested to me there was something more complex going. Additionally, looking at Nilsen and Fossa's chart and seeing similar cycles both with new systems AND with algae issues which had a clear link to a catastrophic event then clearing up with relitively little effort to remediate the problem, what seems reasonable to me is these ecosystems besides being very dynamic also have an inherent check and balance that will "naturally" lean to a system beneficial to corals, sometimes in spite of what the basic water chemistry might be indicating. While it's still way beyond our ability to test for in our aquaria the research showing incredibly complex microbial communities that are possibly unique to their "host" species of coral is probably part of the answer. But part may also be giving the nutrition and feeding requirements of corals. One study Delbeek and Sprung refference in Vol III, pg 576, collected about 1 lb of zooplankton in one day with a meter wide net (picture a 200 gallon tank) and Shimek has a pretty good article on anorexic reef aquariums in the Nov/Dec 2010 of Coral magazine. Feeding corals so they can compete with nuisance algae may be a better long term solution than starving an entire system to eliminate only one undesirable component.

Acropora valida

[victoly]

Your observations on coloration with respect to PAR is interesting, but I think it may be hard to assume that the rest of the measurable variables (temp, salinity, Alk, Ca, Mg, PO4) remain constant while the light (or flow in your other example) are the main drivers for coloration in the species that you mentioned. That totally neglects the "ether" parameters that we either don't know about or can't reasonably measure.

We are really in an impossible hobby that requires knowledge in impossibly diverse fields. We stack the deck in our favor as best we can, but ultimately the people who are really successful and have great tanks have great luck, unlimited time or unlimited funding.

[jolt]

And great mentors too I'll bet!