Elements with No Known Biological Role

[Hans-Werner]

PO4 is currently 0.374 ppm. What do you think about the color at this high PO4 level?

That's exactly what I'm saying. If there is any influence of phosphate on the colors of corals it is positive. If you want vibrant colors avoid low phosphate concentrations. Really low phosphate concentrations will make the colors dull.

 

[Hans-Werner]

I believe PO4 has been wrongly vilified by the companies that produce phosphate removal media and chemicals That way they have a reason to sell you something.

But this is not the only reason. Knowledge from freshwater systems were uncritically applied to marine ecosystems. I am not 100 % sure that the knowledge was always right for freshwater since one nutrient seldom cames alone, but I am sure in reef aquaria it is not the phosphate that makes green algae grow, it is iron and nitrogen. Natural conditions may be different in freshwater with iron and nitrogen rarely limiting.

 

[rtparty]

But this is not the only reason. Knowledge from freshwater systems were uncritically applied to marine ecosystems. I am not 100 % sure that the knowledge was always right for freshwater since one nutrient seldom cames alone, but I am sure in reef aquaria it is not the phosphate that makes green algae grow, it is iron and nitrogen. Natural conditions may be different in freshwater with iron and nitrogen rarely limiting.

I’ve been of that same belief. Too much freshwater influence early on in the saltwater hobby and many of those old beliefs and myths are still hanging on.

However, I’m not educated enough to write about such things to argue my points. Just beliefs I’ve held for a long time after seeing my own systems and how they run. I don’t test for nitrate and phosphate almost ever. Been this way since at least 2010 when I started dosing Vodka and MB7. These days I dose Bacto Balance and MB7. I see no need to test N or P.

 

[Randy Holmes-Farley Verified Community Expert]

There were also references early on, and which may or may not have been shown to be incorrect since then, that demonstrated reduced rates of calcification or abnormal calcification with elevated phosphate:

https://aslopubs.onlinelibrary.wiley.com/doi/abs/10.4319/lo.1979.24.5.0935

Long term phosphate (2 µM) and nitrogen (20 µM urea + ammonium) enrichment of a patch reef at One Tree Island, Great Barrier Reef, caused >50% suppression of reef calcification. This is attributed primarily to the phosphate. It is suggested that this effect is involved, together with algal competition and the more usually accepted depression of temperature, in reducing the growth rate of reefs adjacent to upwellings.

ENCORE: The Effect of Nutrient Enrichment on Coral Reefs. Synthesis of Results and Conclusions

Coral reef degradation resulting from nutrient enrichment of coastal waters is of increasing global concern. Although effects of nutrients on coral re…

www.sciencedirect.com

Nitrogen additions stunted coral growth, and phosphorus additions had a variable effect.

Coral calcification rate and linear extension increased in the presence of added phosphorus but skeletal density was reduced, making corals more susceptible to breakage.

Coral mortality, not detected during the initial low-loading phase, became evident with increased nutrient dosage, particularly in Pocillopora damicornis.

 

[jda]

I started keeping corals in the early 1990s. Most of the corals that we had, which were few, would not do well in tanks of today. PPE zoas, Purple Monster, Blue Polyps Digi (later ORA), German Blue Polyp Acropora, etc. all did better when heavy-in, heavy-out philosophy of reefing with low residual numbers. You have kinda seen these corals phase out of the hobby for less needy ones. You HAD to keep water near NSW if you wanted to keep more than colt corals and mushrooms. These were VHO and 5500/6500k MH days, so not the stone ages with only NO fluorescent bulbs.

I would caution anybody not to blame Freshwater for the keeping of old. They had no influx of less sensitive corals where they could just let the more sensitive ones die out of the hobby. Besides, without the discus and african cichlid breeders having lots of credit at the LFS for their babies, there would not likely be a saltwater hobby - nobody else could afford it.

Also, in the CFL and chaeto-like-crazy days, people changed a lot of water. This was, and still is, enough to double a chaeto ball in a few weeks. The tools did not exist for folks to try and outsmart what is in a salt mix, so you had no other choice.

I remember a cabbage coral coming in on an order to the LFS and people fighting over it. Fox coral almost started a fist fight.

 

[Hans-Werner]

There were also references early on, and which may or may not have been shown to be incorrect since then, that demonstrated reduced rates of calcification or abnormal calcification with elevated phosphate:

I think most controlled trials had this result, cited from the abstract of the ENCORE article: "... phosphorus additions had a variable effect. Coral calcification rate and linear extension increased in the presence of added phosphorus but skeletal density was reduced, making corals more susceptible to breakage."

If I recall it right effect of ammonium and phosphate combined were worse, phosphate alone hat little effect on coral mortality.

I think the finding with the reduced calcification and increased coral mortality was in an older trial at Hawaii where sewage was used to increase nutrients. There has been some criticism that other effects like water cloudiness had not been taken into account when assessing for reduced calcification and coral mortality.

 

[jda]

You can see the calcification results in your own home if you do it right. You need a wide variety of acropora.

Get your po4 at 1-5 ppb and no3 below 1 and watch your coralline take off like crazy. You have to still feed a ton and export a ton since we never want to be nitrogen or phosphorous limited, just no3 and po4 limited. Chateo grows way faster too, and about half of my corals - other half do not care. You can raise the po4 and no3 back up again and watch the coralline and corals slow down. I am NOT saying that massive amounts of coralline are a good thing in a reef tank - I hate the stuff, but my urchins love it.

I have read a lot and it seems that the end of the study on what corals do or don't have slower calcification depends mostly on the species used. Most GBR studies include an entire reef worth of species whereas the studies with Poci, Porites are somewhat flawed to me since I have seen these grow in sewage tanks under screw-in Home Depot CFL lighting and they are very adaptable.

My general though lately is to choose what you want to do and then pick corals that fit it. If you want to keep some of the old-time LE acropora, you absolutely need no3 and po4 pretty close to NSW, but there are many beautiful ones that do not need this. ...so it matters, but it might not matter any particular hobbyist.

 

[X-37B]

I started keeping corals in the early 1990s. Most of the corals that we had, which were few, would not do well in tanks of today. PPE zoas, Purple Monster, Blue Polyps Digi (later ORA), German Blue Polyp Acropora, etc. all did better when heavy-in, heavy-out philosophy of reefing with low residual numbers. You have kinda seen these corals phase out of the hobby for less needy ones. You HAD to keep water near NSW if you wanted to keep more than colt corals and mushrooms. These were VHO and 5500/6500k MH days, so not the stone ages with only NO fluorescent bulbs.

I would caution anybody not to blame Freshwater for the keeping of old. They had no influx of less sensitive corals where they could just let the more sensitive ones die out of the hobby. Besides, without the discus and african cichlid breeders having lots of credit at the LFS for their babies, there would not likely be a saltwater hobby - nobody else could afford it.

Also, in the CFL and chaeto-like-crazy days, people changed a lot of water. This was, and still is, enough to double a chaeto ball in a few weeks. The tools did not exist for folks to try and outsmart what is in a salt mix, so you had no other choice.

I remember a cabbage coral coming in on an order to the LFS and people fighting over it. Fox coral almost started a fist fight.

I still practice heavy in/out. No3 <5 but is almost always 1 when tested.
Po4 < .1 and runs around .05.
However I also run my alk at 7.

I still think many forget that no3 and po4 are what your export system is not removing.
Alk in the early 90's was run very high as I remember so it could handle the higher no3 and po4 levels.
Alk 15-18? What?
Late 80's book for reference.
Who wants to give these alk levels a go today?

 

[Hans-Werner]

If you want to keep some of the old-time LE acropora, you absolutely need no3 and po4 pretty close to NSW, but there are many beautiful ones that do not need this. ...so it matters, but it might not matter any particular hobbyist.

Yes, I agree, many fragged and "bred" clones are much more tolerant for typical reef tank conditions today and some look good under almost any conditions. It is a kind of Darwinian selection (Darwin got his ideas on natural selection looking at the results of selective breeding of pigeons and other livestock).

 

[livinlifeinBKK]

I'm getting in on this thread extremely late and sorry if I'm repeating what was already said (I'd read through it if it werent quite so long since it's a little late here). Aside from rare earth metals, radioactive elements of course, and I'm sure a few others out there, I believe MOST organisms which are considered to be more complex such as vertebrates have at least a tiny bit of a couple dozen or so elements in their body which play some biological function in molecules (or even individual elements) located somewhere in the body. Some are present in such minute amounts, however, so there would never be a reason to supplement or test for them. I'd certainly imagine different organisms such as corals, sponges, echinoderms, and many other marine invertebrates would have many additional elements within their bodies that they require and also lack some required by invertebrates.

Honestly what I think would be really interesting would be to determine how many elements are present in various wild marine fish in modern times (not biologically necessary, and many times harmful) due to the pollution of the ocean.

 

[jda]

Smaller less stable tanks, heavy blue lights, wider range of traces and higher residual no3 and po4 - I label this generation in the hobby as the bio-cube generation (since Nemo came out), so I guess that it is Bio-Cubism or Nemoism moreso than Darwin, but the same thing.

I once had a theory that higher no3 and po4 levels were better for corals with cut-spectrum lights. The lighting without far-red and the ability to move energy between photosystems and not getting the high energy waves below 400nm was better if calcification and cellular processes were slowed/interrupted a bit by hither residual no3 and po4 levels. This was mostly borne out of old vs new reefing techniques where you absolutely did not really want no3 to get very high if you ran massive amounts of full-spectrum MH on Son Agro ballasts with 1000+ par, but they did fine with more NSW level parameters.

Somehow this theory got out and somebody contacted me. Not sure if Dana did it, or what. In any case, this is in the early stages of being studied at a well-known place. It has been a few months since I heard anything, and they do have actual research to benefit the world and not just folks with corals in glass boxes, but it appears to be happening. It ties in with some other research they are doing about how slightly elevated no3 and po4 is helpful, but then starts to hurt - I told them my theory that it was likely the abundance of other types of N and P and not the actual rise in no3 and po4 that mattered, but that no3 and po4 rising could act as a semi-poison. They are on that too. If any of this is right, as terrestrial no3 and po4 rises in seawater, previously destinations with more cloud cover that were previously not considered good places for coral growth might now be on the table.

 

[Pod_01]

Just fascinating how discussion on elements with no known biological role ends up discussing P/PO4.

I guess that after salinity and Alk the next most important/critical parameter should be P/PO4.

But for the fun of it I went through my old notes…. (when I was good at killing corals and I was looking for guidance)

I do recall scratching my head even back then. All these other sites and sources state zero or low Phosphate (R2R was no different) and here phosphate was number one.
I still need to relearn that lesson every so often when my P/PO4 drops and I am like what is going on.

 

[Randy Holmes-Farley Verified Community Expert]

I do recall scratching my head even back then. All these other sites and sources state zero or low Phosphate (R2R was no different) and here phosphate was number one.
I still need to relearn that lesson every so often when my P/PO4 drops and I am like what is going on.

Much of the impetus for wanting low N and P was the idea that the ocean was a good thing to mimic. Problem is, mimic just part of it (soluble N and P) and not all of it (such as high availability of particulate foods that contain N and P) was likely not the best idea.

 

[Doctorgori]

phosphate wasn’t even discovered by man until the post “Radium epoch”

 

[Stoneyed]

Super interesting article
Looks like a pretty large variation in both macro and trace elements. Also interesting that the zoox don't follow the same trend.

 

[Doctorgori]

Super interesting article
Looks like a pretty large variation in both macro and trace elements. Also interesting that the zoox don't follow the same trend.

Sounds interesting can you translate that into “low IQ” English for some of us? (the gist of the article)

 

[jda]

Lower no3 and po4 tanks worked better in the olden days when people fed more. Nearly everybody had much no3 with deeper sand beds being common. po4 would be low while the sand bed was binding well. After a number of years, if neglected, people would say that the sandbed was a time bomb, but it just meant that it was full of so much inert material that it could not longer turn no3 into N gas. The sandbed also had already bound a bunch of po4 and the water level was rising. Of course the phrase Time Bomb was inaccurate and the phenonomen was just masking a lack of husbandry.

In the current times, people try as hard as they can not to feed much, don't want much sand and to have as little light as possible. Also with smaller tanks means smaller fish to feed. You might need more no3 and po4 if there are not other sources of nitrogen and phosphorous around.

Live rock tanks are a great source of nitrogen and phosphorous, IMO. Bacteria through the slime coat is one of the main ways that true coral get N, P and C without much of a energy waste. Dry/dead rock tanks are lacking in this at least for a long time - they may never get it.

A really smart guy once wrote this in 2004. It still works if you feed well, export well and grow stuff. I find it interesting that nitrate is in the 'others' column and phosphate is in the 'critical' column - this is most likely to no3 not being as much of an issue when people used sand and live rock. Chemistry and biology has not changed since we were born, but habits of reefers has, I guess. What has always worked still does... new stuff can work too.

 

[Reefahholic]

I believe PO4 has been wrongly vilified by the companies that produce phosphate removal media and chemicals That way they have a reason to sell you something.

I agree.

I’m convinced that one of the number #1 problems in a reef tank is low or depleted Phosphate. What an absolute mess my take became initially due to the depleted phosphate even while trying to dose it up.

 

[Reefahholic]

That's exactly what I'm saying. If there is any influence of phosphate on the colors of corals it is positive. If you want vibrant colors avoid low phosphate concentrations. Really low phosphate concentrations will make the colors dull.

I love phosphorus/phosphate. It’s so important. I typically don’t run this high, but I will say it helped rid the last of the Dino’s. For some reason they don’t thrive in higher phosphate levels. I’m unsure if that is because the phosphate does something to them specifically or if it’s just helping the microorganisms multiply and they start to gain the upper-hand in the battle. Either way…I don’t like to be below about .06-.08 and I prefer to be 0.1++ up to about 0.2

Nitrogen seems less important, but I’ll tell you a funny story about how I realized how beneficial it is to have “some” whatever that number is, since most of us run very different NO3 levels.

One day I noticed that my NO3 was zero. I had a horrible Cyano bloom. My anemone was looking very sick and deflated. This was back in the days of “stump remover” if I remember correctly. Diesel helped me figure out a dose for 1 ppm and I let it rip. Instantly… that sick deflated anemone blew up like a balloon and got sucked into a powerhead. It was then that I realized that NO3 was likely a very important part of the chemistry.

Going back to PO4. I’ve seen more issues related specifically to PO4 that I’m convinced it’s one of the most important parameters we have. Mine has become quite stable now, but the first year was a nightmare.

One last story. We had a guy who reached out to everybody in our group. He was loosing SPS left and right. Big system. All his parameters were looking really good until I got down to total phosphorus and phosphate. We had about 9-10 ppb and 0.03 ppm. System was younger I think under 1 year at that time. I said…I think your phosphate is too low. He’s says…you think so?? I said yes I do. Can you try to dose it up to about .08ppm and let’s see what happens. The corals gained color, never lost another piece even until now. Last I talked to him things were going really well, and he was up around 0.2 and said the tank was running beautifully. Probably lost 3-4K in acros before that.

Now when people are having problems…PO4 is one of the first parameters I check.

 

[Reefahholic]

I still think many forget that no3 and po4 are what your export system is not removing.

Yep, we’re removing all the organics before they break down into N&P. Fish poop/pee, feeds, etc.

You could just run it like Glenn and pull all the skimmers and use the power filter and organic carbon to export. Not sure how well
that works for PO4 longterm, but I know it will easily handle NO3. I’d just keep my skimmer for aeration.

I think I could handle the PO4 with natural bacteria, and I’m sure the carbon dosing would take it down a little also. Sounds like a win win. Feed the corals, zero export of trace elements or organics, and grow massive colonies. Corals should be fat, full, healthy. System should be rock solid with super healthy bacteria and biome population.

Right @glennf I don’t think he’s had a skimmer since like 2017 or so.