Fenton Reactions in the Reef Tank. Good or Bad

[Gomi's Reef]

In another post I have seen Randy mention that Fenton reactions are bad.

I was thinking that a Fenton reaction to facilitate the production of hydroxl radicals would boost the oxidative power of hydrogen peroxide dosing and that would facilitate the breakdown and removal of organic waste and thus be an overall positive.

What am I missing here?

 

[Randy Holmes-Farley]

I do not think highly oxidizing species are desirable loose in the tank.

The elements of Fenton reactions, such as hydrogen peroxide, hydroxyl radicals, and other radical species, are highly toxic to living organisms. The toxicity of the reactive oxygen species comes from their ability to oxidize a large number of cellular constituents. Toxicity mechanisms include DNA disruption, oxidation of proteins and amino acids, and lipid peroxidation of membrane fatty acids.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC106541/#:~:text=The elements of Fenton reactions,large number of cellular constituents.

 

[Gomi's Reef]

I do not think highly oxidizing species are desirable loose in the tank.

The elements of Fenton reactions, such as hydrogen peroxide, hydroxyl radicals, and other radical species, are highly toxic to living organisms. The toxicity of the reactive oxygen species comes from their ability to oxidize a large number of cellular constituents. Toxicity mechanisms include DNA disruption, oxidation of proteins and amino acids, and lipid peroxidation of membrane fatty acids.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC106541/#:~:text=The elements of Fenton reactions,large number of cellular constituents.

I appreciate this point Randy, but in the low doses we are talking about it is truly a concern? 1ml/10g of 3% peroxide is quite dilute. Or will it trigger a cascade of radical formation? My radical formation chem is a tad rusty

 

[Randy Holmes-Farley]

I appreciate this point Randy, but in the low doses we are talking about it is truly a concern? 1ml/10g of 3% peroxide is quite dilute. Or will it trigger a cascade of radical formation? My radical formation chem is a tad rusty

I'm not claiming that at low doses it is a problem, but the same is true of any toxin at low enough doses.

Fenton reactions may well happen when folks dose hydrogen peroxide. Whatever effects folks observe is related to all of its chemistry in aggregate, which may include Fenton chemistry.

That leaves the question being:

1. Purely scientific: is it happening and what happens as a consequence
or
2. Function: is there something one can do to promote the fenton chemistry , and is doing so useful

boosting iron substantially while dosing hydrogen peroxide at the same time may be the best way to test #2, but I personally would want to leave my oxidizing chemistry in a separate location, such as an ozone chamber with the effluent passed over GAC. Organism tissues are all organics, and hitting them with oxidizers more than is needed may be a problem.


FWIW, oxidation will modify organics, but it doesn't remove them. It reduces yellowing but leaves the organic in a modified form. Aside from reduced yellowing, it is unclear if that is helpful.

 

[Gomi's Reef]

I'm not claiming that at low doses it is a problem, but the same is true of any toxin at low enough doses.

Fenton reactions may well happen when folks dose hydrogen peroxide. Whatever effects folks observe is related to all of its chemistry in aggregate, which may include Fenton chemistry.

That leaves the question being:

1. Purely scientific: is it happening and what happens as a consequence
or
2. Function: is there something one can do to promote the fenton chemistry , and is doing so useful

boosting iron substantially while dosing hydrogen peroxide at the same time may be the best way to test #2, but I personally would want to leave my oxidizing chemistry in a separate location, such as an ozone chamber with the effluent passed over GAC. Organism tissues are all organics, and hitting them with oxidizers more than is needed may be a problem.


FWIW, oxidation will modify organics, but it doesn't remove them. It reduces yellowing but leaves the organic in a modified form. Aside from reduced yellowing, it is unclear if that is helpful.

I know this conversation has been helpful.
Thank you for the time and clarification. I think we are on the same page, I do want to test and tinker, but I'm not sure it is wise.

Food for thought.

Thank you kindly

 

[Gomi's Reef]

FWIW, oxidation will modify organics, but it doesn't remove them. It reduces yellowing but leaves the organic in a modified form

My understanding from reading some of the scientific literature on foam fractionation was that water treated with oxidants can increase skimmer efficiency. Quite significantly from what I read

 

[Randy Holmes-Farley]

My understanding from reading some of the scientific literature on foam fractionation was that water treated with oxidants can increase skimmer efficiency. Quite significantly from what I read

I discuss that topic in one of my ozone articles, but different folks see effects in different directions:

Oxidation of Organics by Ozone: Skimming and Nutrients

---

Another result of breaking some organics into smaller, more hydrophilic bits (Figure 3 and 4) is that it often increases their bacterial biodegradability.27-29 Therefore, the ozone may need only to start the degradation process, and bacteria in the aquarium can finish off the organics by uptake and metabolism. Large humic acid molecules, for example, are converted by ozonation into smaller fragments that are more readily taken up and metabolized.29 This process may, in fact, be why some aquarists report drops in nutrient levels after initiating ozone. It is not because ozone directly impacts either nitrate or phosphate (it does not react directly with either), but the newly bioavailable organics may drive bacterial growth, just as adding ethanol (e.g., vodka) or sugar might. The growing bacteria need nitrogen and phosphate, and if they satisfy those needs by taking up nitrate and phosphate, the levels of those nutrients in the water may drop. That effect, however, may be only temporary as the initial burst of new bioavailable organics winds down, and a new stable state is reached with lower levels of organic material and similar levels of inorganic nutrients.

Skimming is a complex process that has many subtleties. The previous sections have discussed how ozonation modifies organic molecules , and we can then extrapolate how those processes impact skimming. Years ago it was widely claimed that ozone use increased skimming, and I claimed then that I didn't see how that could happen directly. Most organic compounds likely to be found in significant quantities in a reef aquarium will become more polar and likely less skimmable after it reacts with ozone. Figure 3, for example, shows how oleic acid (readily skimmed) gets converted into more polar compounds that will not be so readily skimmed as they will not be as strongly attracted to an air water interface.

A small portion of organic molecules in reef aquarium water may become more skimmable if, for example, they become more hydrophobic after reaction with ozone. They may also become more skimmable if they were totally hydrophobic before ozone and were transformed into molecules with polar and nonpolar parts (called amphiphilic) which more readily absorb onto an air water interface and are skimmed out.

Are there other ways that skimming might be increased besides these two processes? I hypothesized in a previous article that it was due to the growth of bacteria (either in the water itself, or bound to surfaces), and possibly also the release of new organic molecules as they grew, that caused the effects some aquarists observed.

It seems as if the tide of opinion has turned, however, and most aquarists now claim that the amount of skimmate is reduced significantly when using ozone. Many claim that the collection of skimmate has nearly stopped in their aquaria when starting ozone. Why the difference compared to past opinion? That's hard to say, and may depend on the types and qualities of the skimmers available now compared to years ago, as well as changes in other husbandry practices. In any case, the overriding experience of many aquarists today is that skimming is reduced, and the presumed reason is that the organics are being made chemically less skimmable by ozone. The remaining organics would then be removed more by bacterial processes than before the initiation of ozone in the same aquarium.

 

[taricha]

in 2016 I was reading about some UV/TiO2/h2o2 advanced oxidation processes.
I took apart a UV sterilizer and put in some strips of cheap titanium sheeting I bought online.

I was curious if it would do anything interesting.
I ran it in a container and measured the ORP (with and without H2O2), but I did not detect a surge as might be expected from oxidizing radicals.

I also isolated my aquarium sump from the display, and ran the UV+Titanium in there for a few days. Nothing much interesting happened, It grew a film of cyano on the water surface, which would not be expected if it was making a bunch of oxidizing radicals.

I didn't mess with it further. Maybe the oxidized layer that forms on titanium is not actually TiO2 or maybe it lacks the photo-oxidation properties because it's so thin. Or maybe my online titanium purchase wasn't genuine.

 

[aquariome]

I do not think highly oxidizing species are desirable loose in the tank.

The elements of Fenton reactions, such as hydrogen peroxide, hydroxyl radicals, and other radical species, are highly toxic to living organisms. The toxicity of the reactive oxygen species comes from their ability to oxidize a large number of cellular constituents. Toxicity mechanisms include DNA disruption, oxidation of proteins and amino acids, and lipid peroxidation of membrane fatty acids.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC106541/#:~:text=The elements of Fenton reactions,large number of cellular constituents.

For many years I have worked with Heterogenous Photocatalysis (HPC) which is another Advanced Oxidation Process (AOP). The AOP group includes the Fenton processes (hydrogen peroxide with iron) and Ozone + UVC. Producing the Hydroxyl radical under photo excitation is well known and is the action by which Ozone absorbs UVC light in the stratosphere. This has been called the "detergent" of the atmosphere. Ozone however is not miscible in water so what is not converted to the hydroxyl radical will bubble out and being an oxidizer can be toxic in sufficient quantity indoors. Hydrogen peroxide must be added as a feed stock which is problematic under most scenarios.

Using a semi-conductor photocatalyst which is activated by UVA vs UVC bandwidths makes it a superior method for energy consumption and safety. HPC under photoexcitation produces a redox reaction at the photocatalytic surface from water molecules. Since these last for nano-seconds due to their strong oxidative strength, they do not enter the water column but remain proximate to the photocatalyst where they oxidize adjacent organics from the water or simply consume themselves back to water. This same redox reaction does produce a number of ROS from available oxygen (singlet Oxygens, Superoxide anions and peroxides.) These are relatively mild oxidizers and therefore persistent sanitizers. These have a beneficial effect in the water column and can reduce colonization on surfaces (Algae). The problem we encountered using this technology in a saline environment, the ions (Na+ and Cl-) interfered with the redox reaction of photocatalysis, but that is another story.

Given the community knowledge, and the contributors of this threads interest in these fields, I would like to ask if an opinion on general AOP application(s) and ultimately marketable to the Reef community. Do either of these strike a chord with your pursuits?

1.) Oxidation of organics to reduce (Fishy smells) VOCs, treat water quality and deactivate pathogens as a support feature working in conjunction with traditional methods.
2.) As a stand-alone alternative for use as an environmental purification system specifically for quarantine (prophylaxis or vector mitigation).


John

 

[taricha]

Given the community knowledge, and the contributors of this threads interest in these fields, I would like to ask if an opinion on general AOP application(s) and ultimately marketable to the Reef community. Do either of these strike a chord with your pursuits?

1.) Oxidation of organics to reduce (Fishy smells) VOCs, treat water quality and deactivate pathogens as a support feature working in conjunction with traditional methods.
2.) As a stand-alone alternative for use as an environmental purification system specifically for quarantine (prophylaxis or vector mitigation).

I'll answer this way. The idea of oxidizers as pathogen control is of interest to me.
We in the hobby are getting better at detecting/measuring pathogenic bacteria and connecting that to coral/fish disease. However, (opinion) our tools to remedy the bacterial pathogens aren't very good.

Our toolkit currently looks like this:
antibiotics - either dip or full system, single targeted one if well researched and good data, or a blend if desperate and no idea what to do.
dip antiseptics - like iodine or H2O2.
oxidizers on a full system - H2O2 (usually ineffective), and some few use tiny doses of hypochlorite and say it's helpful - but most find that idea really undesirable.
Competing with "good bacteria" - this has very little evidence of effectiveness in hobby systems, but is commonly attempted.

All these have limitations (effectiveness, unintended targets, toxicity risks, persistence in system, abx resistance, etc) and it makes the tools that detect bacterial pathogens much less valuable, because our toolkit to remedy those pathogens sorta sucks.
no idea if other oxidizers might be helpful tool or not, but that's my answer to what I think your question is.

 

[Randy Holmes-Farley]

On question 1, other methods such as activated carbon, polymer organic binders, and skimming all keep tank water smells at acceptable levels in most situations. If oxidation is desired, confined use of ozone works well, and many folks add hydrogen peroxide directly to the water. In general, my concern with tank wide oxidation is damage to living tissues of all sorts.

In question 2, if one had evidence that pathogens could be killed without damage to the main organism of interest, that would be interesting.

 

[aquariome]

I'll answer this way. The idea of oxidizers as pathogen control is of interest to me.
We in the hobby are getting better at detecting/measuring pathogenic bacteria and connecting that to coral/fish disease. However, (opinion) our tools to remedy the bacterial pathogens aren't very good.

Our toolkit currently looks like this:
antibiotics - either dip or full system, single targeted one if well researched and good data, or a blend if desperate and no idea what to do.
dip antiseptics - like iodine or H2O2.
oxidizers on a full system - H2O2 (usually ineffective), and some few use tiny doses of hypochlorite and say it's helpful - but most find that idea really undesirable.
Competing with "good bacteria" - this has very little evidence of effectiveness in hobby systems, but is commonly attempted.

All these have limitations (effectiveness, unintended targets, toxicity risks, persistence in system, abx resistance, etc) and it makes the tools that detect bacterial pathogens much less valuable, because our toolkit to remedy those pathogens sorta sucks.
no idea if other oxidizers might be helpful tool or not, but that's my answer to what I think your question is.

Taricha,

My apologies for my tardy response.

I concur with your insights into Antibiotics, they can do more harm than good if not target specific.

Hydrogen peroxide is a reasonable sanitizer in the water column somewhat like hypochlorous acid, but without UV activation, it won't be forming the hydroxyl radical. It needs to be constantly added to be a true persistent sanitizer like chlorination. HPC continually produces Reactive Oxygen Species ROS that persist as residual sanitizers. The superoxide anion produced is actually part of our innate cellular immunity. The hydroxyl radical is not a persistent sanitizer or part of the water column in our systems since this reaction only occurs within the reactor. Too much, and persistent sanitizers can go after the beneficial bacteria in any treatment technique, so I am not trying to sterilize the aquarium. I only expect enough to reduce free floating algal cells and assist in clarification.

I will need to study iodine, as I am not familiar with its pathways in Aquaria. HPC mineralizes; effective on organics, but inorganics are basically left alone. A medication I am familiar with is Methylene Blue which is used to treat fungal infections. To get rid of Methylene Blue in an aqueous solution, there are really only two ways to accomplish this task, evaporate the water, collect the methylene blue powder and incinerate it, or use an AOP to oxidize it in place. We actually use MB Dye as a target to test the logarithmic efficiency of our photocatalytic response. This is why I am pursuing the technology for Aquaria envision this to be a subtle and behind the scenes treatment, basically burning the pathogens underwater. It also oxidizes NH3/4 to NO2 and NO2 to NO3, but that is an entirely separate issue and best left to our naturally occurring nitrifying bacterial friends.

I see two pathways. One is this subtle supportive always there first line of defense, or the alternative is scale it to eliminate all bacteria good or bad turning the quarantine chamber into a decontamination chamber. It sounds to me like you are in the first camp of add to the tool kit?

John

 

[aquariome]

On question 1, other methods such as activated carbon, polymer organic binders, and skimming all keep tank water smells at acceptable levels in most situations. If oxidation is desired, confined use of ozone works well, and many folks add hydrogen peroxide directly to the water. In general, my concern with tank wide oxidation is damage to living tissues of all sorts.

In question 2, if one had evidence that pathogens could be killed without damage to the main organism of interest, that would be interesting.

Randy,

Yes, Activated Carbon and other sequestering materials are the go-to control for VOC's, but they do not eliminate them in-situ and require replacement and disposal.

In this paper, I co-authored, https://phys.org/news/2023-09-highly-efficient-photocatalytic-based-titanium.html, a focus was on a chemical free hot tub. The Hot Tub industry has also tried Ozonation and Hydrogen Peroxide with very limited results. We saw a very significant deactivation of hot tub, lab grown and wild samples of bacteria using our reactors.

We too were interested in the effects of the ROS produced and emulated the acute toxicity and long-term toxicity testing done on rainbow trout by the mining industries required for releasing wastewater into tributaries. We used Guppies. They were very happy and forced us to concentrate on rehoming the constantly occurring generations from these live bearers. We also noticed a reduction in maintenance compared to our traditional bioreactor control tank (Algae and Water exchanges). This is why my interest in Aquaria was initially piqued. I do have a focus on the VOCs that cause off-flavoring and endemic pathogens in the Recirculated Aquaculture industry, but since there are less than 100 operating Recirculated Aquaculture Systems reported in the USA, I would consider the 800,000+ Reef Aquariums a better audience for innovation?

I don't want to be presumptuous, but do you prefer the concept of a decontamination/isolation chamber?

John

 

[Randy Holmes-Farley]

Randy,

Yes, Activated Carbon and other sequestering materials are the go-to control for VOC's, but they do not eliminate them in-situ and require replacement and disposal.

In this paper, I co-authored, https://phys.org/news/2023-09-highly-efficient-photocatalytic-based-titanium.html, a focus was on a chemical free hot tub. The Hot Tub industry has also tried Ozonation and Hydrogen Peroxide with very limited results. We saw a very significant deactivation of hot tub, lab grown and wild samples of bacteria using our reactors.

We too were interested in the effects of the ROS produced and emulated the acute toxicity and long-term toxicity testing done on rainbow trout by the mining industries required for releasing wastewater into tributaries. We used Guppies. They were very happy and forced us to concentrate on rehoming the constantly occurring generations from these live bearers. We also noticed a reduction in maintenance compared to our traditional bioreactor control tank (Algae and Water exchanges). This is why my interest in Aquaria was initially piqued. I do have a focus on the VOCs that cause off-flavoring and endemic pathogens in the Recirculated Aquaculture industry, but since there are less than 100 operating Recirculated Aquaculture Systems reported in the USA, I would consider the 800,000+ Reef Aquariums a better audience for innovation?

I don't want to be presumptuous, but do you prefer the concept of a decontamination/isolation chamber?

John

I do not know that this is a problem looking for a solution as opposed to a technology looking for a problem. The drawbacks to current organic technologies are fairly minor and the techniques work as well as is needed, so any potential replacement technology would need to also fit that description. Completely removing organics or bacteria is not desirable.

Yes, if one is going to be using an oxidation technology, I would certainly prefer it to be done remotely, as such as the way ozone is used in a reactor of some sort. There are so many different organisms in a reef tank that may be more delicate than fish, including bacteria, that to know a new technology is OK might require substantial testing.

As I see it, there are three issues with organics in the water in a reef tank:

1. Yellowing of the water due to light absorbing organics. The concern is partly aesthetic and partly light penetration to photosynthetic organisms. Generally, removal of the organics cannot be overdone from this perspective if the changes are made slowly enough.

2. Effect of organics on the population of different bacterial species, from pathogens to needed species. These exact effects are just beginning to be understood using genomics testing. Altering the organics with any technology risks changing the balance of bacteria, for better or worse.

3. Larger organisms that feed off organics (corals, sponges, etc.) may not thrive as well if organics are reduced.

 

[aquariome]

Taricha,

My apologies for my tardy response.

I concur with your insights into Antibiotics, they can do more harm than good if not target specific.

Hydrogen peroxide is a reasonable sanitizer in the water column somewhat like hypochlorous acid, but without UV activation, it won't be forming the hydroxyl radical. It needs to be constantly added to be a true persistent sanitizer like chlorination. HPC continually produces Reactive Oxygen Species ROS that persist as residual sanitizers. The superoxide anion produced is actually part of our innate cellular immunity. The hydroxyl radical is not a persistent sanitizer or part of the water column in our systems since this reaction only occurs within the reactor. Too much, and persistent sanitizers can go after the beneficial bacteria in any treatment technique, so I am not trying to sterilize the aquarium. I only expect enough to reduce free floating algal cells and assist in clarification.

I will need to study iodine, as I am not familiar with its pathways in Aquaria. HPC mineralizes; effective on organics, but inorganics are basically left alone. A medication I am familiar with is Methylene Blue which is used to treat fungal infections. To get rid of Methylene Blue in an aqueous solution, there are really only two ways to accomplish this task, evaporate the water, collect the methylene blue powder and incinerate it, or use an AOP to oxidize it in place. We actually use MB Dye as a target to test the logarithmic efficiency of our photocatalytic response. This is why I am pursuing the technology for Aquaria envision this to be a subtle and behind the scenes treatment, basically burning the pathogens underwater. It also oxidizes NH3/4 to NO2 and NO2 to NO3, but that is an entirely separate issue and best left to our naturally occurring nitrifying bacterial friends.

I see two pathways. One is this subtle supportive always there first line of defense, or the alternative is scale it to eliminate all bacteria good or bad turning the quarantine chamber into a decontamination chamber. It sounds to me like you are in the first camp of add to the tool kit?

John

Taricha,

I looked at Iodine and its application as a dip treatment for corals. The definitive mechanism of its anti-microbial benefits seems to be unresolved. It is so common in wound care and surgical procedures; I think I had simply taken this halogen for granted. Regardless of its pathways, it works reasonably well, and any residue from dipping should be dilute to the aquarium. I believe if any inorganic iodine from this procedure entered the aquarium, it would be oxidized to the organic iodate if subjected to ROS from HPC. https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2023.1085618/full

I went down the rabbit hole. Iodine/Iodide/Iodate.

Iodide and Iodate appear to decrease in aquaria via consumption by biological processes, GAC and purportedly foam fractionation. I believe KI is the preferred delivery method for supplementing as it boosts potassium as well. Again, this should not be a problem as mentioned above.

Thank you for bringing this topic to my attention. Iodate levels were not something I was aware of for Aquaria health since the requisite water exchange (salts) typically replenish. I was focused on Calcium as the "building block" required via water replacements. Iodine is so important to us (Thyroid) that iodized salt has become the staple. Makes perfect sense in the aquarium biome as well.

Now I must read up on strontium.

 

[Randy Holmes-Farley]

Now I must read up on strontium.

I personally do not think strontium is needed by organisms we typically keep. I believe too many people confound consumption with “needed” or “useful”. It generally just slips into depositing calcium carbonate in place of similarly looking calcium.

 

[aquariome]

I do not know that this is a problem looking for a solution as opposed to a technology looking for a problem. The drawbacks to current organic technologies are fairly minor and the techniques work as well as is needed, so any potential replacement technology would need to also fit that description. Completely removing organics or bacteria is not desirable.

Yes, if one is going to be using an oxidation technology, I would certainly prefer it to be done remotely, as such as the way ozone is used in a reactor of some sort. There are so many different organisms in a reef tank that may be more delicate than fish, including bacteria, that to know a new technology is OK might require substantial testing.

As I see it, there are three issues with organics in the water in a reef tank:

1. Yellowing of the water due to light absorbing organics. The concern is partly aesthetic and partly light penetration to photosynthetic organisms. Generally, removal of the organics cannot be overdone from this perspective if the changes are made slowly enough.

2. Effect of organics on the population of different bacterial species, from pathogens to needed species. These exact effects are just beginning to be understood using genomics testing. Altering the organics with any technology risks changing the balance of bacteria, for better or worse.

3. Larger organisms that feed off organics (corals, sponges, etc.) may not thrive as well if organics are reduced.

Randy,

It is a solution that addresses many problems. It is waggishly called the holy grail of green water chemistry for this very reason.

Item 1. Has been a verifiable result.

Item 2. A reasonable amount of ROS within the water column does not overcome the protective mucilaginous coating that beneficial bacteria form once colonized. Dosing with Ozone or Hydrogen Peroxide provides a good narrative. Free floating algal cells and bacteria however do appear to have a challenge in simply increasing CFU when exposed to ROS enhanced water. Corals and their zooxanthellae live primarily close to the surface where wind/wave and intense sunlight occur at the interface. A high concentration of ROS is the result in this zone. This is why I inquire if it is best for a prophylaxis for disease or an environmental treatment?

Item 3. I am working with various Coral types to see if a negative response occurs long term. I once had concerns that molting of invertebrates could be impacted long term, but this has not been observed. Again, the use of Ozone, UVC and Hydrogen Peroxides are reliable analogs as fellow members of the AOP class and have shown no challenges outside of over application of their toxicity. Life giving sunlight has made many organisms that survive in shallow seas develop protection from its intensity. We know that far blue light coupled with a smidge of red is best for Macro Algae growth. UVA is the transition from visible far blue light and does handily penetrate the Ozone layer but also penetrates water to a significant depth. It is a normal condition for phytoplankton to encounter. Concentrating our photo-excitation to a specific UVA band using LED emitters (365nm) which excites Anatase TiO2 overcomes the shotgun approach of traditional mercury bulbs which produce such a wide range of visible and invisible light including the UVC which does damage to the Thiamine dimer if employed to generate the Hydroxyl Radical from Ozone. We have been trying these commercially available methods for decades (Ozone and UVC), a preferential alternative is needed.

John

 

[aquariome]

I personally do not think strontium is needed by organisms we typically keep. I believe too many people confound consumption with “needed” or “useful”. It generally just slips into depositing calcium carbonate in place of similarly looking calcium.

Randy,

Phew. Thank you for saving me from a spiral into strontium!

Cheers,

John

 

[aquariome]

All,
From the previous answers, I believe the following are the best parameters for application as another tool in the "toolkit". Not meant to replace, but to support the overall biome.

1. Reducing yellowing of the water and thereby promoting light penetration is good.

2. Eliminating pathogens and competitive bacteria is acceptable, but not at the cost of the beneficial bacteria.

3. A slow reduction of organics is actually preferred especially as it may impact the growth of Corals, Sponges, etc.

4. It must have no negative effect on larger organisms (Fish, Inverts and Corals).

Question I have is bacteria are a good target in the water column, but do you believe scaling up for diatoms and phytoplankton's reduction would ever be beneficial or simply cause problems to the biome? Could that be better suited in a FOWLR vs a Reef setup?

A focus on only treating the water column is consistent across these requirements.

Thanks for your earlier replies.

John