Test Method: Possibly Measuring a Polyquat Algaecide in Reef Tank Water (tracking Vibrant dose)

[taricha]

This is interesting, but includes a lot of speculation, which I've tried to make clear.

A. Test Method: Possibly Measuring a Polyquat Algaecide in Reef Tank Water (tracking Vibrant dose)
(almost. Kinda, but not really.)


B. Hypothesis: The algaecide in question is a cationic polymer, which combines with anionic surfactant, SDS (sodium dodecyl sulfate) to produce structures that are large enough to scatter light and thus the cloudy water from that process can be measured by a hanna checker. Detection by this method can be done in distilled water at much higher concentrations, but it is not sensitive enough to detect a recommended dose (1 mL product / 10 Gallons) in new saltwater. But in my reef tank water, this method does form easily quantifiable cloudiness in response to addition of the product, suggesting an interaction with organics / particulates etc in reef water that makes the measurement more sensitive. (I have no idea if it will work in anyone else's water or not.)

C. Method: (I'm not going to do a bunch of tweaking on this, so I'll leave it here for reference and others can run with it or not.)
I'm using the hanna ULR P meter hi736, and 10% SDS and below is the method as I have been using it. The product being added to the tank is Vibrant.
- Take 10 mL tank water, add to a hanna cuvette (use that as blank, C1)
- add 0.50mL of 10% SDS to the cuvette
- cap and invert 10x to mix (do not shake, avoid bubbles)
- start 3 minute countdown
- gently invert one last time ~30-40 sec before measurement (likely unnecessary).
- measure in checker

D. Here's some data showing what applying this method to Vibrant doses in my tank generates.

My tank has a history of Vibrant and Algaefix use, both of which are detected by this method. Neither product had been added to the tank in 2+ months.
Prior to the additions shown on this chart, my tank water gave consistent zeros using this measurement. I added 1/2 of a recommended dose (recommended = 1mL / 10 Gal) of Vibrant and measured ~30min later. Then repeated with another 1/2 dose and 30min wait.
After 3 full days I added another recommended dose split in half again and measured the same way. I did duplicates for all measurements for the first 2 days. (I'll explain the red dots in a later post.)
My tank runs a skimmer 24/7 and some GFO.

It's worth pointing out that this is not a direct measurement of the polyquat itself, because doing so in distilled water or fresh mixed Instant Ocean does not have near this sensitivity. My speculation is that the chemical interacts with organics in my tank water, so it's probably more accurate to say I'm measuring Vibrant-associated-material, after it interacts with my tank water. This Vibrant associated material seems to deplete from the water mostly (but not totally) over 3 days. If your tank water is like mine, the method ought to work similarly. If you do a bunch of water changes (I don't) then it probably won't. So this isn't true quantification, but it may be possible to track the relative rates of removal of a dose of this material from the water in systems other than mine. But if the amount of organics in your water dramatically decreases, then this method of detection would become less responsive to Vibrant.

(I'll post background theory for those interested in reading more, and more observations later.)

 

[taricha]

Here's some background, theory and further reading for those interested.
Some measurements I made using this principle at much higher vibrant concentration.

C. Product reaction with sodium dodecyl sulfate (SDS)
When figuring out why the QAC titration kit coagulated and failed, I stumbled upon the observation that when the (cationic) polyquat is added to excess SDS (an anionic surfactant), a cloudy solution is formed by the reaction and the cloudiness is proportional to the amount of polyquat added.

I used this fact to compare the concentrations of the polyquat in each product by the cloudiness / optical density generated upon addition of the products to 5mL of water with 0.250mL of 10% SDS. Below is the resulting data.

It is the same story as the other two methods of comparison. The 5.4% polixetonium chloride products - Algae Control and Algae Cleanout are easily distinguished as higher concentration than the 4.5% concentration product, Algaefix. Vibrant and Vibrant freshwater are on the other hand indistinguishable in concentration from Algaefix. The slope of the 5.4% products (average) comes out to be 19.8% higher than the other 3 products' average, as predicted by their labels.

Explanation from RHF including a nice article with illustrations of the combinations of SDS and cation polymer.

As I continue to work through the details, I would just add that this is a known effect. I've encountered it in my professional work.

What happens is the very hydrophilic ammonium cations on the polymer complex with the very hydrophilic sulfate anions on the SDS, leaving the very hydrophilic parts shielded by the hydrophobic tails of the SDS (the dodecyl part) and some of the less hydrophilic parts of the polymer. The consequence is the outer surfaces of the complex are far less hydrophilic and soluble than the individual components, and micelles and larger precipitated structures that scatter light and become visible are formed.

Here's a discussion of the process happening:

https://www.mdpi.com/2073-4360/11/1/51/pdf-vor

Here's another paper (abstract) that I found relevant.
Microstructures formed in a mixed system of a cationic polymer and an anionic surfactant

"... In solutions of low SDS concentration, bilayer fragments, small vesicles and disc-like aggregates form. As the SDS concentration is increased and approaches charge neutrality, the solution becomes turbid.
...At higher concentrations of SDS, resolubilization took place and a variety of microstructures appeared: vesicles, disc-like and thread-like structures. Upon increased surfactant excess, resolubilization was completed with the formation of spheroidal micelles."

 

[taricha]

Observations on the reaction:
The time of 3 minutes need not be exact, but it's built in to the timer of the checker so it's convenient. the measurement seems stable until almost 10 min and then is noticeably decreased past 10min.
The amount of SDS is not particular either, as long as it's enough to be in excess. cutting it in half (0.250mL 10% SDS for 10mL tank water) left my tank water "zero" cloudy. So if you find that your zero tank water stays cloudy after mixing, then it's possible you may need to go a little higher on the amount of SDS.
The wavelength doesn't matter much because the cloudiness scatters at all wavelengths (slightly more at shorter wavelength), you just want the most sensitive checker possible - ULR P is ideal, but there are others that would also work probably.

 

[taricha]

Observations and speculation on my tank data:

Again, my speculation is that since vibrant alone is undetectable in distilled or clean new Instant Ocean at these concentrations, I am guessing that the binding to organics allows a change in the manner of the combination with SDS (different size/shape/ratio etc) thus making more visible material.
This implies that what I'm detecting is mostly Vibrant that has already attached to some stuff and is still in the water. An interesting observation on that point is the red data around day 4 on the chart.
I created a sand storm by blowing a bunch of sandbed material into the water.


I measured again 2 hours later after it all had cleared (the red data in the above chart). Duplicate measures showed no major decrease in the value. This is consistent with the speculation that the material I'm measuring had already bound to stuff, because it did not attach to and get removed by the skimmed / sinking sandbed material.
To go really out on a limb of speculation, if this material is already bound when it hits and mixes with my high organics water, then little of it might be available to attach to the target algae. This would be consistent with my tank history with algaefix. Months ago I dosed every 3 days, (sometimes every 2 days - overdose) for weeks and weeks and the decrease in GHA was very slow. It's possible most of it was binding with other targets in the water before meeting my GHA.
I would speculate further that if I had run GAC or done a bunch of water changes, causing my tank water to have less organics, then the algaefix might have attached more to the target algae.

Based on the above chart, dosing every 3 days (or especially every two days as I sometimes did) could lead to some amount of accumulation of this detectable material in the water - by which I mean the amount detected 3 full days after the dose is not zero.

(I halted my heavy usage of Algaefix months ago when I noticed I hadn't seen any of my peppermint shrimp in a few days - over the next several weeks other inverts were also affected.)

These observations and speculations point in some conflicting directions. If the measured material is already bound to organics, then is it less effective on algae? Maybe that's why I couldn't knock out GHA with consistent heavy usage.
But the flip side - if this stuff is already bound, ineffective, and just circulating in the water, then one would think it ought not be very much of a problem for tank inhabitants. But I saw issues with inverts during (and for weeks after) my time of heavy usage. Or maybe that wasn't the stuff in the water, but was the cumulative effect of the small portion of the dosed amounts that did bind to surfaces.

 

[taricha]

Here's what it looked like after 20 days (from the 1st dose). Interestingly, there is still detectable material in the water.
Red stars on day 0 (duplicates) bracket the two half-doses of Vibrant that were added ( = 1x dose)
Darker red stars on day 3 bracket the two half-doses that were added (making the second full dose)

This suggests another possible short- to medium-term fate for the Vibrant active ingredient, in a minority of systems. In some systems with a lot of organics in the water (not running GAC) it's possible that most of it is neither quickly removed from the water by binding to skimmable material nor permanently bound to sediments and surfaces.
Instead, it seems it could have a long dwell time in the water by binding to organics that are not well skimmed. The rise from day 4 to 10 could mean some of it initially attached to biofilms and cells etc but was slowly shed into the water (perhaps as those cells died and were broken down, or sloughed off from biofilm into the water). Just a guess.

 

[J1a]

This is interesting, but includes a lot of speculation, which I've tried to make clear.

A. Test Method: Possibly Measuring a Polyquat Algaecide in Reef Tank Water (tracking Vibrant dose)
(almost. Kinda, but not really.)


B. Hypothesis: The algaecide in question is a cationic polymer, which combines with anionic surfactant, SDS (sodium dodecyl sulfate) to produce structures that are large enough to scatter light and thus the cloudy water from that process can be measured by a hanna checker. Detection by this method can be done in distilled water at much higher concentrations, but it is not sensitive enough to detect a recommended dose (1 mL product / 10 Gallons) in new saltwater. But in my reef tank water, this method does form easily quantifiable cloudiness in response to addition of the product, suggesting an interaction with organics / particulates etc in reef water that makes the measurement more sensitive. (I have no idea if it will work in anyone else's water or not.)

C. Method: (I'm not going to do a bunch of tweaking on this, so I'll leave it here for reference and others can run with it or not.)
I'm using the hanna ULR P meter hi736, and 10% SDS and below is the method as I have been using it. The product being added to the tank is Vibrant.
- Take 10 mL tank water, add to a hanna cuvette (use that as blank, C1)
- add 0.50mL of 10% SDS to the cuvette
- cap and invert 10x to mix (do not shake, avoid bubbles)
- start 3 minute countdown
- gently invert one last time ~30-40 sec before measurement (likely unnecessary).
- measure in checker

D. Here's some data showing what applying this method to Vibrant doses in my tank generates.

My tank has a history of Vibrant and Algaefix use, both of which are detected by this method. Neither product had been added to the tank in 2+ months.
Prior to the additions shown on this chart, my tank water gave consistent zeros using this measurement. I added 1/2 of a recommended dose (recommended = 1mL / 10 Gal) of Vibrant and measured ~30min later. Then repeated with another 1/2 dose and 30min wait.
After 3 full days I added another recommended dose split in half again and measured the same way. I did duplicates for all measurements for the first 2 days. (I'll explain the red dots in a later post.)
My tank runs a skimmer 24/7 and some GFO.

It's worth pointing out that this is not a direct measurement of the polyquat itself, because doing so in distilled water or fresh mixed Instant Ocean does not have near this sensitivity. My speculation is that the chemical interacts with organics in my tank water, so it's probably more accurate to say I'm measuring Vibrant-associated-material, after it interacts with my tank water. This Vibrant associated material seems to deplete from the water mostly (but not totally) over 3 days. If your tank water is like mine, the method ought to work similarly. If you do a bunch of water changes (I don't) then it probably won't. So this isn't true quantification, but it may be possible to track the relative rates of removal of a dose of this material from the water in systems other than mine. But if the amount of organics in your water dramatically decreases, then this method of detection would become less responsive to Vibrant.

(I'll post background theory for those interested in reading more, and more observations later.)

Nice work!

This is what I think though: a running aquarium tends to have a fluctuating level of organics. The interday and intraday variation in the organic level may affect the cloudiness of the mixture.

Would u think using a fresh IO with a known amount of some organics in a stand-alone container eliminate this variation?

 

[taricha]

Would u think using a fresh IO with a known amount of some organics in a stand-alone container eliminate this variation?

Theoretically, yes I think that would work.
But practically, I do not know what compounds are involved here, except that I have seen enough to say that my skimmate is not a source for these compounds that combine with vibrant polymer in an easily measurable way. Likewise I can say that GAC does completely remove these compounds, whether or not the vibrant polymer has attached to them. That is to say, vibrant attached to these compounds is easily detectable, adding GAC removes all of this easily detectable combined material, and it also removes the material that would allow later additions of vibrant to be detectable - after running my water through GAC, I can no longer easily detect new vibrant doses.

 

[J1a]

After re-reading your posts. I think I misunderstood the objective.

Are you interested more about in-situ dynamic of polyquat in a (typical) running aquarium? Specifically the amount remain in the water column?

 

[taricha]

Are you interested more about in-situ dynamic of polyquat in a (typical) running aquarium? Specifically the amount remain in the water column?

Yeah, there are several ways of simply detecting the polyquat and quantifying it.
I was hoping to do just what you said: give the ability to track the polyquat fate in the tank. Hoping it'll apply to a typical tank, but it seems like this only works well at detecting it in systems not running GAC.

 

[taricha]

Here's what I mean about detection sensitivity being almost entirely dependent on the organics in the water.

Below is how the detection of a dose of vibrant works on the ULR P meter when adding a 1x dose of vibrant to either my tank water, or my tank water that has been treated with GAC (1tsp / 1L water on orbital shaker 24hr) then GAC removed, and finally that GAC treated tank water with my tea-colored skimmate added (0.050mL skimmate in 10mL of GAC-treated tank water).

	Tank Water	TW treated with GAC	TW+GAC then + skimmate
No Vibrant	0	0	0
+1x Dose Vibrant	25 to 35	4	3

this seems consistent with the idea that most of this detected material is the polyquat bound to organics that can be removed by GAC, but it doesn't really work the same way with the organics collected in skimmate.

So if you run GAC, almost totally out of luck with this method.

 

[J1a]

Yeah, there are several ways of simply detecting the polyquat and quantifying it.
I was hoping to do just what you said: give the ability to track the polyquat fate in the tank. Hoping it'll apply to a typical tank, but it seems like this only works well at detecting it in systems not running GAC.

In this case, how about adding an excess amount of some organics (got to try it, maybe some amino acid, or algae filtrate) to the test sample so that the test is not too dependent on the organic level of the system.

 

[taricha]

how about adding an excess amount of some organics (got to try it, maybe some amino acid, or algae filtrate) to the test sample so that the test is not too dependent on the organic level of the system.

Yep. Afraid that since nothing in skimmate is the "right stuff," finding the right organic for this purpose might be tricky. Algae filtrate is an interesting idea.

 

[MnFish1]

Thanks for doing the work - and posting to the research forum!!! @taricha

 

[MnFish1]

According to some, Algaefix is gone from the water in 48 hours. I know the question is 'where does it go'

 

[taricha]

It looks like ~a month to get back to within an error bar of zero.

This data can only plausibly apply to a tank with high organics, no GAC, few water changes etc.
@Dan_P data collection on cleaner water will be much more widely applicable.

My logging may be thought of as a bad-case scenario, an attempt to explain how undesirable outcomes might happen for some tanks, even then, I have no idea if what I'm measuring relates in any way to bad outcomes in tanks.

The caveats to this are almost too significant and too numerous to list...

1) I don't know for sure what I'm measuring. I'm increasingly leaning toward it being the vibrant polyquat bonded to organics in the water that are poorly skimmed. (but they are removed rapidly by GAC.)
2) the trends in clean water that Dan generates will look nothing like this, probably. So it has zero applicability to most systems.
3) I have no idea if what's detected is harmful at all. It's certainly much less potent than the un-bonded material. May be totally harmless, and merely of curiosity in the sense "where does this chemical end up?"
4) I don't know if some part of it is re-released material from algaefix use several months ago.
5) The material certainly has no noticeable long term suppression effect on algae in my system.
(other caveats I'm probably forgetting...)

 

[MnFish1]

It looks like ~a month to get back to within an error bar of zero.

This data can only plausibly apply to a tank with high organics, no GAC, few water changes etc.
@Dan_P data collection on cleaner water will be much more widely applicable.

My logging may be thought of as a bad-case scenario, an attempt to explain how undesirable outcomes might happen for some tanks, even then, I have no idea if what I'm measuring relates in any way to bad outcomes in tanks.

The caveats to this are almost too significant and too numerous to list...

1) I don't know for sure what I'm measuring. I'm increasingly leaning toward it being the vibrant polyquat bonded to organics in the water that are poorly skimmed. (but they are removed rapidly by GAC.)
2) the trends in clean water that Dan generates will look nothing like this, probably. So it has zero applicability to most systems.
3) I have no idea if what's detected is harmful at all. It's certainly much less potent than the un-bonded material. May be totally harmless, and merely of curiosity in the sense "where does this chemical end up?"
4) I don't know if some part of it is re-released material from algaefix use several months ago.
5) The material certainly has no noticeable long term suppression effect on algae in my system.
(other caveats I'm probably forgetting...)

Thanks for listing the caveats

 

[MnFish1]

It looks like ~a month to get back to within an error bar of zero.

This data can only plausibly apply to a tank with high organics, no GAC, few water changes etc.
@Dan_P data collection on cleaner water will be much more widely applicable.

My logging may be thought of as a bad-case scenario, an attempt to explain how undesirable outcomes might happen for some tanks, even then, I have no idea if what I'm measuring relates in any way to bad outcomes in tanks.

The caveats to this are almost too significant and too numerous to list...

1) I don't know for sure what I'm measuring. I'm increasingly leaning toward it being the vibrant polyquat bonded to organics in the water that are poorly skimmed. (but they are removed rapidly by GAC.)
2) the trends in clean water that Dan generates will look nothing like this, probably. So it has zero applicability to most systems.
3) I have no idea if what's detected is harmful at all. It's certainly much less potent than the un-bonded material. May be totally harmless, and merely of curiosity in the sense "where does this chemical end up?"
4) I don't know if some part of it is re-released material from algaefix use several months ago.
5) The material certainly has no noticeable long term suppression effect on algae in my system.
(other caveats I'm probably forgetting...)

It would be nice If you would (maybe you have - I just havent see that post) - explain what the various stars and error bars are - for example - there do not seem to be any error bars on many of the data points. There is also not much of a discussion of what an 'error bar of zero' means - Again I'm not talking about vibrant - per your research - Vibrant and the rest are equal - so - I'll say algaefix. Do you have any idea as to what the 'toxic dose' to reef inhabitants of algaefix is - as compared to the toxic dose to algae? Could that be why repeated doses be recommended - i.e. - given your 'pharmacokinetics' - is it possible that even with repeated doses - that it would kill algae - but not livestock?

 

[Dan_P]

1) I don't know for sure what I'm measuring. I'm increasingly leaning toward it being the vibrant polyquat bonded to organics in the water that are poorly skimmed. (but they are removed rapidly by GAC.)

I have the same thoughts, but am not losing too much sleep over it right now because it is so darn consistent. I can measure this Vibrant-SDS cloudiness in freshly prepared Instant Ocean or my aquarium water. I have found no water that can make this effect go away. I tested 10% skimmate in aquarium water and the precipitate is still there, as if no skimmate were present. I will provide the numbers.

2) the trends in clean water that Dan generates will look nothing like this, probably. So it has zero applicability to most systems.

The only thing that seems to decrease the amount of precipitate (Vibrant in solution) is a “biological” surface. Not clean glass nor clean aragonite sand. I am currently growing biofilms on glass microscope slides and exposing them to Vibrant. Will the slimy slides gradually suck up more and more Vibrant? Will it be proportional to surface area? Will Vibrant slow or stop biofilm formation?

3) I have no idea if what's detected is harmful at all. It's certainly much less potent than the un-bonded material. May be totally harmless, and merely of curiosity in the sense "where does this chemical end up?"

I have four different algae cultures being exposed to Vibrant right now. We should get some information here but will not answer all questions yet. And I will not feed my beloved Mexican turbo snails Vibrant poisoned algae I will try to capture the poisoning of Ulva through nutrient consumption studies.

4) I don't know if some part of it is re-released material from algaefix use several months ago.

I performed a 48 hour test on aquarium sand exposed to Vibrant. What stuck to it does not get released in 48 hours, at least to the limit of detection. More work needed here.

5) The material certainly has no noticeable long term suppression effect on algae in my system.
(other caveats I'm probably forgetting...)

I wonder if the model for Vibrant distribution in the aquarium is something like this…

1-Vibrant binds to biological surfaces, biofilms included. Can it bind to dissolved organic matter? Irreversibly like it apparently does to biological surfaces?

2-Vibrant may take time to bind to surfaces. If there is a large amount of non-algae surfaces and a little bit of target surface, Vibrant might never reach its target surface. I have just scratched the surface of the kinetics of binding. Also, there is a limit to what we can learn from concentration decreases of Vibrant. How do I measure the proportion of Vibrant bound to sand vs to a piece of algae in the same container? Attached a fluorescent tag to Vibrant?

3-Vibrant might just latch onto surfaces and stay there until the surface decays away, though there is likely another surface around for it to stick to.

4-How lethal Vibrant is to algae depends on the amount used and the total surface area available to remove it before it latches onto the target algae. Lethality to higher organisms might be related to the lack of a large biofilm to soak it up.

I think others have already brought up many of these ideas. Let there be testing.

 

[MnFish1]

IMHO - and its just that MHO - everyone should stop talking about vibrant - and start talking about algaecides in general. I.e. Algaefix, etc. Seems to me the vibrant ship has sailed

 

[taricha]

1-Vibrant binds to biological surfaces, biofilms included. Can it bind to dissolved organic matter? Irreversibly like it apparently does to biological surfaces?

from the paper you sent me the other day, I think we can say this is possible.

"When added to humic acid, the water treatment algicide and cationic polymer poly[oxy-1,2-ethanediyl(dimethyliminio)-1,2-ethanediyl(dimethyliminio)-1,2- ethanediyl dichloride] (Busan 77, Polyquaternium-42) (Appendix 1, xxix), was found to form insoluble precipitates with high molecular weight humic acids (Matthews et al. 1995). The Polyquaternium-42 studied had an average molecular weight of 3900 amu, and molecular weight range from 600 to 5000 amu. However, soluble complexes were formed with low molecular weight humic acid, with the maximum binding capacity indicating 1:1 molar binding at saturation. The binding was reversible, and gave a reasonable fit to a Langmuir isotherm. Between 10% and 20% of the polymer dose was found to be bound in soluble complexes to naturally occurring humic acid under expected levels of polymer contamination in aquatic conditions (Matthews et al. 1995)."

They also talk about how this humic material significantly reduced the effect of the polyquats.

A bit more speculatively, way back we discussed my water having some measurable UV fluorescence. The excitation-emission properties of the fluorescent material in my water seems to fit what researchers describe as humic-like fluorescent material found in marine/estuary waters.