Everything in Reef Chemistry is a Simplification

[Randy Holmes-Farley]

There is nothing inherently wrong with simplification. It’s how almost all types of chemistry become useful.

But a drawback to simplification is that users may not know when something is oversimplified and becomes wrong in some scenario not envisioned by the original author.

Many/most times, reefing chemistry is not so critical that these differences matter, but sometimes they do and/or the discrepancies add together to give a real difference.

What are examples where reefers can possibly be misled by oversimplification?

Brine refractometers used as if they were true seawater refractometers. Brine and seawater have different relationships of refractive index to salinity.

pH meters calibrated without concern for the temperature of the standards or tank (there are two different effects here: the pH meter response vs temp and the actual pH of the buffer vs temp).

Using alkalinity as a gauge of bicarbonate/carbonate availability without regard for the pH or borate levels. (Seachem used to sell a salt with massively high borate, potentially misleading all measurements and pH changes the amount of bicarbonate ate at a given alkalinity).

Using icp to gauge trace element bioavailability and toxicity without regard for chemical form. Cyanide gas and nitrogen gas are examples of different chemical forms of nitrogen with different toxicity.

Just because a chemical is in a bottle does not mean it usefully makes it to the intended organisms (e,g., magnesium in kalk).

Any salinity measuring device we use when the water deviates substantially from natural ratios of the major ions (such as sulfate) can give imperfect answers.

Food and pharma grade chemicals and plastics are not necessarily ok (although they usually are). Tin is approved as a stabilizer for food and pharma plastics, for example.

Here are some at the biology/chemistry interface:

Corals take up chemical X so they must need chemical X. Lots of these pushed on reefers (barium, strontium, rubidium, fluoride etc.) but not others (mercury, lead, uranium). Why? What is the evidence justifying some and not others?

Iodine dosing is reported to sometimes induce shrimp to molt, so they must need iodine to properly molt.

This post is just a cautionary tale to make sure folks know that there are complexities to most chemical issues we address. If things seem odd, it may be worth thinking about the chemistry in greater detail than the simplified version.

Happy Reefing!

 

[sixty_reefer]

“Nitrates causes algae” still baffles me…

It’s one of those simplifications that sounds right for many aquarists but reality often seems far more complicated than that.

 

[EnterName]

I have to admit, I have become a Strontium-believer

My corals started acting up and I didn't know what was wrong, so I got an ICP test which came back fine besides Strontium being very low. After dosing Strontium, everything went back to normal within 48 hours and has been stable since.

Edit: I should highlight the word "believer", as I certainly don't know and there are many things contradicting my experience with Strontium

 

[EnterName]

“Nitrates causes algae” still baffles me…

It’s one of those simplifications that sounds right for many aquarists but reality often seems far more complicated than that.

Just think about the ugly phase. After diatoms vanish green hair algae takes over. But even if there is still nitrate and phosphate available there comes a point where it simply dies off. Maybe it's a trace element, maybe it's some bacteria that outperform the hair algae, I don't know. But it is most definitely more complex than just available nutrients or the green hair algae phase would never end.

 

[sixty_reefer]

Just think about the ugly phase. After diatoms vanish green hair algae takes over. But even if there is still nitrate and phosphate available there comes a point where it simply dies off. Maybe it's a trace element, maybe it's some bacteria that outperform the hair algae, I don't know. But it is most definitely more complex than just available nutrients or the green hair algae phase would never end.

I don’t know either, we all have our thoughts but it’s definitely far more complicated than just Nitrate and Phosphate.

 

[Minifoot77]

There is nothing inherently wrong with simplification. It’s how almost all types of chemistry become useful.

But a drawback to simplification is that users may not know when something is oversimplified and becomes wrong in some scenario not envisioned by the original author.

Many/most times, reefing chemistry is not so critical that these differences matter, but sometimes they do and/or the discrepancies add together to give a real difference.

What are examples where reefers can possibly be misled by oversimplification?

Brine refractometers used as if they were true seawater refractometers. Brine and seawater have different relationships of refractive index to salinity.

pH meters calibrated without concern for the temperature of the standards or tank (there are two different effects here: the pH meter response vs temp and the actual pH of the buffer vs temp).

Using alkalinity as a gauge of bicarbonate/carbonate availability without regard for the pH or borate levels. (Seachem used to sell a salt with massively high borate, potentially misleading all measurements and pH changes the amount of bicarbonate ate at a given alkalinity).

Using icp to gauge trace element bioavailability and toxicity without regard for chemical form. Cyanide gas and nitrogen gas are examples of different chemical forms of nitrogen with different toxicity.

Just because a chemical is in a bottle does not mean it usefully makes it to the intended organisms (e,g., magnesium in kalk).

Any salinity measuring device we use when the water deviates substantially from natural ratios of the major ions (such as sulfate) can give imperfect answers.

Food and pharma grade chemicals and plastics are not necessarily ok (although they usually are). Tin is approved as a stabilizer for food and pharma plastics, for example.

Here are some at the biology/chemistry interface:

Corals take up chemical X so they must need chemical X. Lots of these pushed on reefers (barium, strontium, rubidium, fluoride etc.) but not others (mercury, lead, uranium). Why? What is the evidence justifying some and not others?

Iodine dosing is reported to sometimes induce shrimp to molt, so they must need iodine to properly molt.

This post is just a cautionary tale to make sure folks know that there are complexities to most chemical issues we address. If things seem odd, it may be worth thinking about the chemistry in greater detail than the simplified version.

Happy Reefing!

So when calibrating my ph and orp probes it it a good thing that I let the standards sit in the tank till they are the same temp or should I be looking for a specific temp for calibration?

 

[Randy Holmes-Farley]

“Nitrates causes algae” still baffles me…

It’s one of those simplifications that sounds right for many aquarists but reality often seems far more complicated than that.

That’s certainly an extreme simplification, if not outright wrong.

One could equally or more correctly make that statement about a dozen other chemicals and many physical attributes.

 

[Randy Holmes-Farley]

I have to admit, I have become a Strontium-believer

My corals started acting up and I didn't know what was wrong, so I got an ICP test which came back fine besides Strontium being very low. After dosing Strontium, everything went back to normal within 48 hours and has been stable since.

What corals and what does acting up mean?

How low?

What did you add?

 

[Randy Holmes-Farley]

So when calibrating my ph and orp probes it it a good thing that I let the standards sit in the tank till they are the same temp or should I be looking for a specific temp for calibration?

That is much better than having them at different temps, but in the vein of absolute accuracy, pH buffers themselves do change pH with temperature. Many lab buffers do give these temp changes in the bottle. For some types it changes more than others.

Here’s a table of some:

https://documents.thermofisher.com/TFS-Assets/LED/Product-Guides/Orion-pH%20buffer%20values-vs-temperature-inforsheet-I-PHTEMP-EN.pdf

 

[huttoreefer]

somehow I got was able to get rid of bubble algae and green hair with high nitrate and phosphate, but then when I lower them down (N,P), I got bunch of bubble and green hair again. Something I still try to reason why?

 

[Randy Holmes-Farley]

somehow I got was able to get rid of bubble algae and green hair with high nitrate and phosphate, but then when I lower them down (N,P), I got bunch of bubble and green hair again. Something I still try to reason why?

Coincidence? Competitors?

Valonia (bubble algae) is noted to grow better than other algae at low nutrient levels.

It’s also not just growth that leads to detectable issues with algae, but resistance to consumption by the organisms you have. Something might be growing even faster at higher N and P, but also be consumed faster.

 

[EnterName]

What corals and what does acting up mean?

How low?

What did you add?

What corals:

• Small frag of Acropora sp. (sold as "Strawberry Shortcake")
  • Lost all color, polyps retracted
• Large Stylophora pistilla (Milky Stylophora)
  • Lost a lot of color, polyps retracted
• Caulastraea furcata (Candy Cane)
  • Not fully opening, fine now
• Euphyllia paraancora (now classified as "Fimbraphyllia" afaik)
  • Not fully opening, color was still fine.
• Lobophyllia sp. (Green/Orange/Yellow)
  • Lost color and didn't open up / looked deflated
• 2xEntacmaea quadricolor (Bubble-tip anemone)
  • Shrinking to 1/3 of their size, losing color, open mouth.
• Goniopora sp. (agressively growing Green one I got as a free frag a while back)
  • Polyps deflated. Another Goniopora (sold as "Galaxy") did quite ok though
• Montipora capricornis (Red)
  • Lost a bit of color
• Catalaphyllia jardinei
  • Fully retracted, very pale, looked like it was melting away, but fully recovered :)

How low: 2.85mg/L Sr at a salinity of 34.87 PSU

I added ATI ICP Elements Strontium bringing it back to approx. 8 - 9mg/L.

Full disclosure:

• I just recently transferred rocks, corals and fish to a new tank of approx. the same volume (the old tank showed early signs of seam failure). I have changed the lights, but everything ran smoothly for a few weeks before it went downhill.
• Only 100mL of sand was transferred into the new tank, which means it is a "bare bottom tank" at the moment. The previous tank always had low nutrient levels and I wanted to avoid new dry sand binding too much phosphate and causing issues, so I opted to add new sand slowly once everything is stable.

Everything is absolutely fine again, gladfully no losses at all. I started adding the new sand and am countering the phosphate drops with monosodium phosphate dosing.
Just the large Stylophora still needs to gain some coloration back.

As you can see, there are many factors which could have contributed to my corals being unhappy, but it took quite a while for the ICP test to return and only after adding the strontium everything went back to normal quite fast. This is no proof whatsoever, but I don't think it hurts to keep strontium from dropping too low for now.

 

[Randy Holmes-Farley]

What corals:

• Small frag of Acropora sp. (sold as "Strawberry Shortcake")
  • Lost all color, polyps retracted
• Large Stylophora pistilla (Milky Stylophora)
  • Lost a lot of color, polyps retracted
• Caulastraea furcata (Candy Cane)
  • Not fully opening, fine now
• Euphyllia paraancora (now classified as "Fimbraphyllia" afaik)
  • Not fully opening, color was still fine.
• Lobophyllia sp. (Green/Orange/Yellow)
  • Lost color and didn't open up / looked deflated
• 2xEntacmaea quadricolor (Bubble-tip anemone)
  • Shrinking to 1/3 of their size, losing color, open mouth.
• Goniopora sp. (agressively growing Green one I got as a free frag a while back)
  • Polyps deflated. Another Goniopora (sold as "Galaxy") did quite ok though
• Montipora capricornis (Red)
  • Lost a bit of color
• Catalaphyllia jardinei
  • Fully retracted, very pale, looked like it was melting away, but fully recovered :)

How low: 2.85mg/L Sr at a salinity of 34.87 PSU

I added ATI ICP Elements Strontium bringing it back to approx. 8 - 9mg/L.

Full disclosure:

• I just recently transferred rocks, corals and fish to a new tank of approx. the same volume (the old tank showed early signs of seam failure). I have changed the lights, but everything ran smoothly for a few weeks before it went downhill.
• Only 100mL of sand was transferred into the new tank, which means it is a "bare bottom tank" at the moment. The previous tank always had low nutrient levels and I wanted to avoid new dry sand binding too much phosphate and causing issues, so I opted to add new sand slowly once everything is stable.

Everything is absolutely fine again, gladfully no losses at all. I started adding the new sand and am countering the phosphate drops with monosodium phosphate dosing.
Just the large Stylophora still needs to gain some coloration back.

As you can see, there are many factors which could have contributed to my corals being unhappy, but it took quite a while for the ICP test to return and only after adding the strontium everything went back to normal quite fast. This is no proof whatsoever, but I don't think it hurts to keep strontium from dropping too low for now.

It is extremely unlikely an anemone has a use for strontium, so the fact that it suffered along with the hard corals that will consume strontium makes me skeptical that the effect was from the strontium being low and the dosing helping it.

Whatever it was, however, I’m glad it has resolved. :)

 

[sixty_reefer]

A few more that spring to mind, “If you start with dry rock, you’re going to have a terrible ugly stage”, “the ugly stage is normal and unavoidable” and one I see all the time in help threads “white light causes algae”.

 

[ThisIsTheWay]

Tbh, the more I see, the more I suspect that stability issues are what trigger algae. They seem more opportunistic, but if the environment is kept stable and corals are allowed to settle in, then algae seems to chill out a bit.
It recently clicked for me that in my tank, when nutrients drop, especially if they bottom out, I get cyano, but also a TON of algae growth. It's almost like the rock is trying to expel nutrients to equalize with the water, and the algae can use those nutrients faster than corals can pull them from the water column. Also, like I said earlier, stability issues are the trigger.
Also iron. When I dosed iron for my macros I definitely saw an increase in algae growth. Weirdly enough though, I think the algae was still worse when nutrients dropped.

 

[Alexander1312]

What corals:

• Small frag of Acropora sp. (sold as "Strawberry Shortcake")
  • Lost all color, polyps retracted
• Large Stylophora pistilla (Milky Stylophora)
  • Lost a lot of color, polyps retracted
• Caulastraea furcata (Candy Cane)
  • Not fully opening, fine now
• Euphyllia paraancora (now classified as "Fimbraphyllia" afaik)
  • Not fully opening, color was still fine.
• Lobophyllia sp. (Green/Orange/Yellow)
  • Lost color and didn't open up / looked deflated
• 2xEntacmaea quadricolor (Bubble-tip anemone)
  • Shrinking to 1/3 of their size, losing color, open mouth.
• Goniopora sp. (agressively growing Green one I got as a free frag a while back)
  • Polyps deflated. Another Goniopora (sold as "Galaxy") did quite ok though
• Montipora capricornis (Red)
  • Lost a bit of color
• Catalaphyllia jardinei
  • Fully retracted, very pale, looked like it was melting away, but fully recovered :)

How low: 2.85mg/L Sr at a salinity of 34.87 PSU

I added ATI ICP Elements Strontium bringing it back to approx. 8 - 9mg/L.

Full disclosure:

• I just recently transferred rocks, corals and fish to a new tank of approx. the same volume (the old tank showed early signs of seam failure). I have changed the lights, but everything ran smoothly for a few weeks before it went downhill.
• Only 100mL of sand was transferred into the new tank, which means it is a "bare bottom tank" at the moment. The previous tank always had low nutrient levels and I wanted to avoid new dry sand binding too much phosphate and causing issues, so I opted to add new sand slowly once everything is stable.

Everything is absolutely fine again, gladfully no losses at all. I started adding the new sand and am countering the phosphate drops with monosodium phosphate dosing.
Just the large Stylophora still needs to gain some coloration back.

As you can see, there are many factors which could have contributed to my corals being unhappy, but it took quite a while for the ICP test to return and only after adding the strontium everything went back to normal quite fast. This is no proof whatsoever, but I don't think it hurts to keep strontium from dropping too low for now.

I agree with the Strontium point.

I guess the issue which is outlined in this broader post is that claims are being made for individual elements to have a certain effect while there is potentially no scientific paper to back this up.

Or it is based on a simple assumption, i.e., coral skeleton analysis, hence it must be important.

From a scientific standpoint I can see why folks might cringe, and push back on these simplified claimed benefits. It is a valuable opposing force.

Now there is two paths to this: as a reefer, I can either wait 10 years or longer until someone finds out through scientific testing that F or Sr or S are good for coral health, or disprove this point, or let others try it out and apply it if it has proven to be beneficial.

What constitutes beneficial is subjective, in the absence of a scientific backup. So it comes down to the motives of the person who claims it is, and the successful visible long term results of folks not (literally) selling the idea and benefit financially from it.

I am glad that when I started reefing not too long ago, there was a shift towards focusing more on the importance on many of these (not scientifically proven) elements, as this allowed me to be successful (at my own definition) quicker than this seems to have been possible in the past.

My concern is that pushing back constantly on what is not scientifically proven in the context of at home reefing oversimplifies the complexity and difference of what happens in a reef tank, vs a lab experiment, and prevents progress, even if later it comes out that 30-50% of what was recommended had no impact to the overall benefits.

Again, I do think this pushback is needed in principle, from a ‘regulatory’ standpoint, I just wish it was less forceful in the context of this hobby (vs. human medicine), where the main risk we encounter is the waste of money, which seems to be negligible in the context of its overall cost.

 

[sixty_reefer]

Tbh, the more I see, the more I suspect that stability issues are what trigger algae. They seem more opportunistic, but if the environment is kept stable and corals are allowed to settle in, then algae seems to chill out a bit.
It recently clicked for me that in my tank, when nutrients drop, especially if they bottom out, I get cyano, but also a TON of algae growth. It's almost like the rock is trying to expel nutrients to equalize with the water, and the algae can use those nutrients faster than corals can pull them from the water column. Also, like I said earlier, stability issues are the trigger.
Also iron. When I dosed iron for my macros I definitely saw an increase in algae growth. Weirdly enough though, I think the algae was still worse when nutrients dropped.

You’re not alone, a lot of aquarists have reported seeing stronger algae growth when nitrate or phosphate bottom out. It’s one of those things that keeps popping up often enough to make you pay attention.

To be honest, I don’t think we’ve fully figured that one out yet or have a clear scientific explanation for it.

 

[FrugalReeferJon]

“Nitrates causes algae” still baffles me…

It’s one of those simplifications that sounds right for many aquarists but reality often seems far more complicated than that.

The same is true for phosphates. I’ve seen beautiful algae free tanks running with high phosphate levels.

 

[huttoreefer]

You’re not alone, a lot of aquarists have reported seeing stronger algae growth when nitrate or phosphate bottom out. It’s one of those things that keeps popping up often enough to make you pay attention.

To be honest, I don’t think we’ve fully figured that one out yet or have a clear scientific explanation for it.

I'm thinking about bringing my N,P back up like around 35N and 70P. I was happy at first to see my N dropped to 19 and 17P after being high for awhile, but then noticed bubble algae and green hair, also cyan start taking over the tank. But at the same time, I probably just wait for the tank to be stable again on N and P, if this will help out the algae problem.

 

[sixty_reefer]

I'm thinking about bringing my N,P back up like around 35N and 70P. I was happy at first to see my N dropped to 19 and 17P after being high for awhile, but then noticed bubble algae and green hair, also cyan start taking over the tank. But at the same time, I probably just wait for the tank to be stable again on N and P, if this will help out the algae problem.

What units are those, ppm?

I do remember a member a while back who had a similar issue, at the time his phosphate was reading zero and I suggested raising it, I did get quite a bit of heat for that recommendation in the thread.

A few weeks later he messaged me back, he was surprised that raising phosphate didn’t actually resolve the problem, but somehow it did seem to slow the growth.