Are quarantine tanks worth the effort?

[trevorhiller]

So you have 33% success rate in this one fish alone. That is ax66% loss rate. Just think about that for a minute. My store owners only experienced a 3% loss rate on average. Just saying there might be a better way.

Ahh let me clarify that. The Tomini tang came from a online Vendor, I didn't QT it, but they did. The shipping unfortunately didn't work out. I likely wouldn't have had any different luck if it wasn't QTed. The two fish that I have personally QT'ed are both alive and well as stated in my original post.

I think the issue people have with QT is not spending enough time/effort doing it properly. The fish I QTed came out of QT looking healthier and fatter than when they went in. Not to mention conditioned to aquarium life and eating well.

My point was it took 6 months to get a fish that I really wanted so I don't want to jeopardize its health by exposing it to unnecessary disease risk.

Edit to Add:
I am curious about the 3% loss rate. Can you elaborate on what they are doing? I imagine typical shipping losses are higher than that.

 

[Lowell Lemon]

Ahh let me clarify that. The Tomini tang came from a online Vendor, I didn't QT it, but they did. The shipping unfortunately didn't work out. I likely wouldn't have had any different luck if it wasn't QTed. The two fish that I have personally QT'ed are both alive and well as stated in my original post.

I think the issue people have with QT is not spending enough time/effort doing it properly. The fish I QTed came out of QT looking healthier and fatter than when they went in. Not to mention conditioned to aquarium life and eating well.

My point was it took 6 months to get a fish that I really wanted so I don't want to jeopardize its health by exposing it to unnecessary disease risk.

Edit to Add:
I am curious about the 3% loss rate. Can you elaborate on what they are doing? I imagine typical shipping losses are higher than that.

Back in the dark ages I designed and set up central filtration systems using the methods the large wholesaler known as Quality Marine used. I spent time and money traveling to actual wholesale facilities in Los Angeles and other areas to find out how to design systems that would make my customers more successful with processing large quantities of fish and inverts. Phil Shane at the time ran Quality Marine and the name was earned not just a moniker. You would assume that centralizing the filtration system would increase the disease and mortality problems, but the opposite was true. At the time mortality rates reported by my customers before installation of central filtration systems often exceeded 30% and varied by shipments and weather. After following the designs in Quality Marine and other wholesalers the store owners reported 3% or less mortality through the acclimation and holding of their livestock. I often used System Paks that were manufactured by a company called Aquanetics. These were skid mounted Pump, large cartridge filtration with Carbon filtration, heating, (chillers when needed) and rated U.V. sterilizers for parasite control. We coupled them with large trickle towers and industrial sized protein skimmers. We often included Ozone injection. In all honesty I recommended a treatment area off the main systems to treat sick fish when needed. Most of my customers broke down their treatment tanks since they felt they were not needed by the store. Some of the stores maintained the treatment systems to treat customers fish for them. Almost all of my customers were in the Pacific Northwest and had same day delivery from Quality Marine which I am sure helped to mitigate losses. They could order the afternoon before delivery and the next day pick up their shipments at the airport. In a retail environment the quality of employees varies and the use of a central system with acclimation tables reduced the loss rates to the reported levels by the stores.

I managed laboratories back before working in aquarium industry and I was taught that science should provide repeatable results for a wide variety of technicians. It is that background that led me to follow the success of one of the best wholesale operations at the time. I left the industry in the early 2000's to pursue other business ventures.

I also ran a wholesale and acrylic fabrication business building filters, aquariums, and light systems along with maintaining aquariums for Dental clinics, hospitals, restaurants, and corporate offices. Early on I provided interim wholesale saltwater fish and inverts to help increase availability of livestock for local stores. My sources were all west coast wholesalers.

As an aside I had one customer in Portland, OR who never used a central system but had individual tanks all with air stone driven under gravel filtration. He never used power heads just a central blower and individual heaters. His name was Bob, and he was retired and running a store out of his converted one car garage but had owned a large store (Gateway Tropicals) for many years. He had the most impressive collection of fish for sale anywhere on the West Coast. I often saw fish in his tanks like Japanese Pinecone Fish, Nautilus, and other oddities you would never see anywhere for sale. He never had sick fish but one of the things that would happen every day was large water changes. He sold so much volume out of those multiple 20-gallon tanks that his daughter was always topping them off and cleaning every day. He reported his loss rates at about the same of the larger stores I set up. In his practice dilution was the solution. Many ways to success and he was successful. People would drive from California, Seattle, and Vancouver just to pick up fish from his garage.

 

[trevorhiller]

Back in the dark ages I designed and set up central filtration system using the methods the large wholesaler known as Quality Marine used. I spent time and money traveling to actual wholesale facilities in Los Angeles and other areas to find out how to design systems that would make my customers more successful with processing large quantities of fish and inverts. Phil Shane at the time ran Quality Marine and the name was earned not just a moniker. You would assume that centralizing the filtration system would increase the disease and mortality problems, but the opposite was true. At the time mortality rates reported by my customers before installation of central filtration systems often exceeded 30% and varied by shipments and weather. After following the designs in Quality Marine and other wholesalers the store owners reported 3% or less mortality through the acclimation and holding of their livestock. I often used System Paks that were manufactured by a company called Aquanetics. These were skid mounted Pump, large cartridge filtration with Carbon filtration, heating, (chillers when needed) and rated U.V. sterilizers for parasite control. We coupled them with large trickle towers and industrial sized protein skimmers. We often included Ozone injection. In all honesty I recommended a treatment area off the main systems to treat sick fish when needed. Most of my customers broke down their treatment tanks since they felt they were not needed by the store. Some of the stores maintained the treatment systems to treat customers fish for them. Almost all of my customers were in the Pacific Northwest and had same day delivery from Quality Marine which I am sure helped to mitigate losses. They could order the afternoon before delivery and the next day pick up their shipments at the airport. In a retail environment the quality of employees varies and the use of a central system with acclimation tables reduced the loss rates to the reported levels by the stores.

I managed laboratories back before working in aquarium industry and I was taught that science should provide repeatable results for a wide variety of technicians. It is that background that led me to follow the success of one of the best wholesale operations at the time. I left the industry in the early 2000's to pursue other business ventures.

I also ran a wholesale and acrylic fabrication business building filters, aquariums, and light systems along with maintaining aquariums for Dental clinics, hospitals, restaurants, and corporate offices. Early on I provided interim wholesale saltwater fish and inverts to help increase availability of livestock for local stores. My sources were all west coast wholesalers.

As an aside I had one customer in Portland, OR who never used a central system but had individual tanks all with air stone driven under gravel filtration. He never used power heads just a central blower and individual heaters. His name was Bob, and he was retired and running a store out of his converted one car garage but had owned a large store (Gateway Tropicals) for many years. He had the most impressive collection of fish for sale anywhere on the West Coast. I often saw fish in his tanks like Japanese Pinecone Fish, Nautilus, and other oddities you would never see anywhere for sale. He never had sick fish but one of the things that would happen every day was large water changes. He sold so much volume out of those multiple 20-gallon tanks that his daughter was always topping them off and cleaning every day. He reported his loss rates at about the same of the larger stores I set up. In his practice dilution was the solution. Many ways to success and he was successful. People would drive from California, Seattle, and Vancouver just to pick up fish from his garage.

Thanks for taking the time to share.

I do believe UV is a worthy addition to any reef tank. My current tank uses UV and it has been much more successful than my previous tanks. Cleaner water, less bacterial issues, less algae issues, etc.

Although, I will say I have done significantly more research now than I did back in 2016 with my first tank. I’d love to incorporate ozone too, I just need to work out what about my Ultra Reef skimmer is incompatible with ozone.

Regarding the shipping success, I'm sure the same day delivery certainly helped those success rates. A few hours versus a day or two is quite different. Particularly with the current standards of UPS and FedEx in a post-Covid world. I’ve had plenty of overnight deliveries that were anything but. Overnight morning delivery often becomes overnight end of the day or two-day delivery.

I do wonder if the prevalence of fish disease is higher these days because the hobby has grown and the internet has made it easier to obtain livestock. Thus, more fish are going through vendors' tanks bringing with it an elevated risk of disease for each of those fish. Combine that with medicocre shipping standards and increased fish stress, I don't think it's a surprise that comparing days of past and current times is a bit like Apples and Oranges. Not too mention the large number of tanks being setup with "sterile" dry rock these days.

 

[Paul B]

You can now vaccinate your fish.....Who knew?

Review

Dev Biol Stand

. 1997;90:233-41.

Immunization against parasitic diseases of fish​

P T Woo 1
Affiliations expand

• PMID: 9270852

Abstract​

Parasitologists have not, in the past, exploited the immune system to protect fish against parasitic diseases. In the past few years, however, there has been an increased interest in adopting this strategy, and we have made steady and promising progress against a few parasites which are of economic importance. Amyloodinium ocellatum is an ectoparasitic dinoflagellate on brackish and marine fishes, which may also cause problems to aquarium fishes. Antiserum from fish inoculated intraperitoneally (i.p.) with living dinospores of the parasite immobilizes and agglutinates living dinospores; it also reduces parasite infectivity in cell culture. Cryptobia salmositica is a pathogenic haemoflagellate of salmonids on the Pacific coast of North America, causing mortality in semi-natural and intensive salmon culture facilities. A live attenuated vaccine inoculated i.p. protects susceptible juvenile and adult fish for at least 24 months. The protection involves production of complement fixing antibodies, phagocytosis, and antibody-dependent and antibody-independent T-cell cytotoxicity. A monoclonal antibody against a surface membrane glycoprotein (199-200 kDa is therapeutic in that it significantly reduces parasitaemias when inoculated into fish with acute disease. Ichthyophthirius multifiliis is an ectoparasitic ciliate of freshwater fishes with world wide distribution, usually causing disease when fish are stressed and/or when environmental conditions are favourable for parasite multiplication. Live theronts injected into the body cavity protect fish, and monoclonal antibodies with immobilizing activity upon parasites have been developed. There is some evidence of passive transfer of protective immunity from immune to naive fish, and to eggs. Diplostomum spathaceum is an intestinal parasite of gulls; the metacercaria stage of the parasite encyst and causes disease and mortality in numerous species of freshwater fish in Europe and in North America. Fish injected i.p. with sonicated/killed cercariae or metacercariae have fewer metacercariae in the eyes and survives longer. Lepeophtheirus salmonis and Caligus elongatus are parasitic copepods (sea lice), and they are important parasites of Atlantic salmon in cage cultures. A vaccine against fish lice is plausible, and the efficacy of about 20 candidate antigens in protecting fish is being tested.

 

[Paul B]

If you are not bored yet and want to know about immunity in fish:

Ichthyophthirius multifiliis: a model of cutaneous infection and immunity in fishes​

H Dickerson 1, T Clark
Affiliations expand

• PMID: 9914927
• DOI: 10.1111/j.1600-065x.1998.tb01277.x

Abstract​

The parasitic ciliate Ichthyophthirius multifiliis offers a useful system for the study of cutaneous immunity against an infectious microorganism. Naive fish usually die following infection, but animals surviving sublethal parasite exposure become resistant to subsequent challenge. This resistance correlates with the presence of humoral antibodies in the sera and cutaneous mucus of immune fish. A mechanism of immunity has recently been elucidated that involves antibody binding to surface proteins (referred to as immobilization antigens or i-antigens) located on the parasite cell and ciliary membranes. Antibody-mediated cross-linking of i-antigens triggers a response by the parasite resulting in its exit from the host. These effects can be observed directly on the surface of live fish. In addition to allowing the observation of effector responses in vivo, Ichthyophthirius also provides a means to study the ontogeny of the mucosal immune response. The sites of antigen capture and presentation, and the sites of antibody production, are unknown with regard to cutaneous immunity. Because the external epithelial surfaces of fish are often the points of pathogen entry, a basic understanding of the inductive immune mechanisms and immune cell interactions in the skin and gills is extremely important with regard to vaccine development. The development of Ichthyophthirius as an experimental system and how it might be used to address these issues are discussed in this review.

Host responses against the fish parasitizing ciliate Ichthyophthirius multifiliis​

K Buchmann 1, J Sigh, C V Nielsen, M Dalgaard
Affiliations expand

• PMID: 11522410
• DOI: 10.1016/s0304-4017(01)00487-3

Abstract​

Recent studies have shown that fish are able to mount protective immune responses against various parasites. One of the best characterized parasite-host system in this context is the ciliate Ichthyophthirius multifiliis (Ich) parasitizing a range of freshwater fishes. Both specific and non-specific host defence mechanisms are responsible for the protection of fish against challenge infections with this ciliate.

 

[mfinn]

As an aside I had one customer in Portland, OR who never used a central system but had individual tanks all with air stone driven under gravel filtration. He never used power heads just a central blower and individual heaters. His name was Bob, and he was retired and running a store out of his converted one car garage but had owned a large store (Gateway Tropicals) for many years. He had the most impressive collection of fish for sale anywhere on the West Coast. I often saw fish in his tanks like Japanese Pinecone Fish, Nautilus, and other oddities you would never see anywhere for sale. He never had sick fish but one of the things that would happen every day was large water changes. He sold so much volume out of those multiple 20-gallon tanks that his daughter was always topping them off and cleaning every day. He reported his loss rates at about the same of the larger stores I set up. In his practice dilution was the solution. Many ways to success and he was successful. People would drive from California, Seattle, and Vancouver just to pick up fish from his garage.

I remember Bob and all those tanks with undergravel filters.
A friend of mine from Tacoma and I would drive down to the Portland area to hit the shops.
Our last stop would be that garage with the sliding glass door that was hard to get open sometimes.
This was back in the early 90's and I had been in the hobby about 10 years and thought I never most everything, atleast until I saw what he could keep alive in tanks with under gravel filters.

 

[Paul B]

I saw what he could keep alive in tanks with under gravel filters.

I still use an undergravel filter.

 

[92Miata]

I’ve tried QTing everything in my own for about a year and half. Lost in total about 40 fish. It’s stressful, time consuming, resource draining, and last but not least imperfect. Things still get through and then trying to QT large amounts of fish at once just amplifies the above.

I've been keeping fish since about 1990, and marine fish since about 2000, and I don't think I've lost anywhere near 40 fish to disease in total over that time. That's not a shot at you - because these numbers seem pretty typical for the folks who prophylactically treat fish in "sterile" qt settings.

So yes, I absolutely question the value. The method that prescribes stark hospital tanks and treating fish with copper/etc as soon as you get them home kills way more fish than disease does. This is a high stress method, and stress not only makes fish more susceptible to disease, but it outright kills a lot of them.

I take umbrage with people calling prophylactically medicated QT the "safe option".

 

[Subsea]

When Charles Delbrick was curator of San Francisco Aquarium he used ug filters. After 20 years of Jaubert Plenum, I copied Paul’s ug reverse flow. Best decision along with cryptic refugiums.

 

[Subsea]

I've been keeping fish since about 1990, and marine fish since about 2000, and I don't think I've lost anywhere near 40 fish to disease in total over that time. That's not a shot at you - because these numbers seem pretty typical for the folks who prophylactically treat fish in "sterile" qt settings.

So yes, I absolutely question the value. The method that prescribes stark hospital tanks and treating fish with copper/etc as soon as you get them home kills way more fish than disease does. This is a high stress method, and stress not only makes fish more susceptible to disease, but it outright kills a lot of them.

I take umbrage with people calling prophylactically medicated QT the "safe option".

KUDOS to this post.

This is my new “Golden Rule” for Reefing

< I take umbrage with people calling prophylactically medicated QT the "safe option".>

 

[areefer01]

When Charles Delbrick was curator of San Francisco Aquarium be used ug filters. After 20 years of Jaubert Plenum, I copied Paul’s ug reverse flow. Best decision along with cryptic refugiums.

Sure - works for you. So many different ways right? How about the 20,000 gallon reef that Joe Yaiullo created and manages. I pretty much already knew this but this thread reinforced how divisive this hobby can be due to a difference of opinion.

Crazy this thread is.

 

[Subsea]

Sure - works for you. So many different ways right? How about the 20,000 gallon reef that Joe Yaiullo created and manages. I pretty much already knew this but this thread reinforced how divisive this hobby can be due to a difference of opinion.

Crazy this thread is.

@Paul B
Do you know Joe Yaiullo? His 20KG tank is located in Riverhead. Isn’t that where you live on the North Fork?

 

[Lowell Lemon]

@Jay Hemdal has on numerous occasions discussed the impact of propagule pressure on the frequency and severity of ich and other parasite infections in reef tanks.

Very few react to these comments, perhaps because they don't agree, or more likely because they haven't taken the time to try to understand it.

I think an additional, related hypothesis should be advanced.

The noticeable absence of ich on ocean fish is due to the absence of propagule pressure, not immunity acquired from exposure to the parasite.

Think about it.

The ich parasite requires a host to complete its life cycle. Yet, when the prototomont drops from the fish, as it drops to the bottom it is carried by current to who knows where. At the same time, the host fish swims away to who knows where. Just imagine what the concentration of tomonts and theronts would need to be to successfully attach to fish in millions of gallons of water.

1 cubic mile of water = 147,197,952,000 cubic feet =
1,101,117,147,352 gallons.

OK, so perhaps the average reef fish remains in an area the size of a football field to a depth of 25 feet.

That's 1,440,000 cubic feet; only 10,771,200 gallons in a football field 25 feet deep.

So, one Trophont (spot on fish) creates one Protomont which creates one Tomont which creates 200 tomonts which creates 200 Theronts which must attach to a fish host within 48 hours or starve to death.

Where is that life cycle likely to be successful, in the ocean or in an aquarium?

My unproven theory: propagule pressure is responsible for the frequency and severity of parasite infection of aquarium fish; the lack of propagule pressure, not immunity, is responsible for the seeming absence of parasite infection in the ocean.

I would also suggest that most parasitic infections that make it to aquariums most likely occur because of exposure to parasites during the fish's journey through the supply chain rather that infection while in the ocean.

My question of this hypothesis is from the following. "In a drop (one milliliter) of seawater, one can find 10 million viruses, one million bacteria and about 1,000 small protozoans and algae (called "protists"). Feb 22, 2021 Microbial research - Costal Wiki www.coastalwiki.org

Since the above it quantifiable science how can one claim that dilution of protozoa in the ocean prevents ich infection. Jay's own communication indicates he has found and photographed various fish with disease while diving in a bay or estuary area. Is this due to the lack of viruses or bacteria in the water where all the disease was prevalent? Is this due to lower oxygen levels in the area? Are there other environmental factors at play such as pollution or stress by trapping a large quantity of fish in a small area? All of this raises more questions than provides answers. Jay also mentioned that sick fish become prey faster in those situations. So consuming the sick fish has no affect on the predators? Again the statement about dilution is assumed and not connected with established science or observation. The other factor is the presence of many hunger mouths that filter feed in the ocean. What role do these play in disease control?

There is a video of a biologist on R2R giving a speech to aquarist about the ejection water conditions at an atoll where the water passes through lots of hungry mouths and the water exiting the passage way was stripped of the normal load of microscopic life. If I find it again I will post it here.

I believe that with all that microscopic life in the average water sample other natural pathways exist for fish health other than dilution alone. I am not a scientist but I use scientific methods each day to improve the quality of my fabricated products. I employed these same methods way back as a dental laboratory technician. Our dentist customers required repeatable results for success in their practice so we employed science and observation to provide the necessary results in our laboratory.

 

[Lowell Lemon]

Actually Cryptocaryon has caused epizootics in the ocean under specific circumstances - in the Florida Keys, during cold snaps, fish are observed huddling under reef ledges covered in ich. The original thought was that the cold water affected their immunity, and indeed, that might be part of it, but the primary cause was more fish packed in under the ledges, with the tomonts releasing theronts every morning. The theronts did not have to swim through huge amounts of open water to find hosts, the hosts were right there, all packed together. Now, the propagule pressure is skewed in favor of the parasite and the fish got severely infected.

Jay

That is an assumption until it can be repeated via experiment and recorded. Not trying to be harsh here just saying that the hypothesis is unproven at this point. Other factors may be present that lead to this result. Was a skin scraping performed to actually identify the causative organism? I know in your experience you have seen many cases of ich but I have seen and documented other organisms that present the same appearance with a 50% mortality in aquaculture and in aquariums after a temperature increase which also lowers oxygen.

 

[Subsea]

Sure - works for you. So many different ways right? How about the 20,000 gallon reef that Joe Yaiullo created and manages. I pretty much already knew this but this thread reinforced how divisive this hobby can be due to a difference of opinion.

Crazy this thread is.

“this thread reinforced how divisive this hobby can be due to a difference of opinion”

@areefer01
I can remember when differences of opinion were opportunities to learn, not “debates to demean”. Yes, even in politics. I know, I am a dinasour.

 

[areefer01]

“this thread reinforced how divisive this hobby can be due to a difference of opinion”

@areefer01
I can remember when differences of opinion were opportunities to learn, not debates to demean. yes even in politics. I know, I am a dinasour.

Without a doubt. Hope you, and everyone here, has an amazing day.

 

[Lowell Lemon]

“this thread reinforced how divisive this hobby can be due to a difference of opinion”

@areefer01
I can remember when differences of opinion were opportunities to learn, not debates to demean. yes even in politics. I know, I am a dinasour.

A man sharpens a man as iron sharpens iron. From a very old source. Civil discussion is necessary to advance practice in every facet of life. I learn more from discussion including my own wrong assumptions! I am here to exchange and learn not claim the high ground. Good day all!

 

[areefer01]

@Paul B
Do you know Joe Yaiullo? His 20KG tank is located in Riverhead. Isn’t that where you live on the North Fork?

His MACNA 2022 presentation is amazing. While I did not see it live in person I am glad it has been made available on youtube.

 

[Gregg @ ADP]

I should also point out that ALL public aquariums that are AZA accredited, MUST utilize a quarantine process. With all of those aquariums using quarantine, do you think they are wrong or have fish that don't live appropriate captive lifespans?

2.7. Quarantine
2.7.1. The institution must have holding facilities or procedures for the quarantine of newly arrived
animals and isolation facilities or procedures for the treatment of sick/injured animals.
2.7.2. Written, formal procedures for quarantine must be available and familiar to all paid and unpaid
staff working with quarantined animals.
2.7.3. Quarantine, hospital, and isolation areas should be in compliance with standards/guidelines
contained within the Guidelines for Zoo and Aquarium Veterinary Medical Programs and
Veterinary Hospitals developed by the American Association of Zoo Veterinarians (AAZV), which
can be obtained at: www.aazv.org/resource/resmgr/files/aazvveterinaryguidelines2016.pdf

Jay

As you know, i think there is more value in managing aquariums as complete ecosystems rather than as swimming pools with fish in them. Not just from a pathogenic perspective, but an environmental/conditions perspective. No need to rehash that whole conversation.

But in my experience, pub aquariums are slow to adapt. I read last year that a public aquarium…can’t remember which one…was taking the controversial route of removing UV sterilizers from its systems. That’s great. Some of us haven’t touched a UV in 20 years. Why? Primarily due to the both the low probability of achieving the desired outcome, but then also because they indiscriminately take beneficial organisms out. Just a very low ROI all the way around. But they are still public aquarium staples.

What I would like to see more of from public aquariums is researching and collecting real data on establishing and managing systems ecologically vs prophylactically. The public aquarium ideology is due for some paradigm shifting, and it starts with real research on this.

I mean, forgive me for not just putting blind trust in the judgement of the AZA. Take this recent comment from research being promoted by the AZA regarding captive welfare of cetaceans:

“In terms of animal welfare, we’re thinking about their mental health as well,” said Miller. “The general public has a perception that dolphins need a large habitat because they think of them living in the wild. But if you’re a human, would you rather live in a cozy house with lots of things to do or a large place with nothing to do?”

Ummm…what??? Aside from the very obvious fact that dolphins are not humans, they’re not even adapted to “live in a cozy house with lots of things to do”. I’ve seen plenty of wild dolphins…can’t remember ever seeing one that looked bored.

But this is the judgement being leaned on for standards of care? Yeah, it might be time to look at things differently.

 

[threebuoys]

My question of this hypothesis is from the following. "In a drop (one milliliter) of seawater, one can find 10 million viruses, one million bacteria and about 1,000 small protozoans and algae (called "protists"). Feb 22, 2021 Microbial research - Costal Wiki www.coastalwiki.org

Since the above it quantifiable science how can one claim that dilution of protozoa in the ocean prevents ich infection. Jay's own communication indicates he he's found and photographed various fish disease while diving in a bay or estuary area. Is this due to the lack of viruses or bacteria in the water where all the disease was prevalent? Is this due to lower oxygen levels in the area? Are there other environmental factors at play such as pollution or stress by trapping a large quantity of fish in a small area? All of this raises more questions than provides answers. Jay also mentioned that sick fish become prey faster in those situations. So consuming the sick fish has no affect on the predators? Again the statement about dilution is assumed and not connected with established science or observation. The other factor is the presence of many hunger mouths that filter feed in the ocean. What role do these play in disease control?

There is a video of a biologist on R2R giving a speech to aquarist about the ejection water conditions at an atoll where the water passes through lots of hungry mouths and the water exiting the passage way was stripped of the normal load of microscopic life. If I find it again I will post it here.

I believe that with all that microscopic life in the average water sample other natural pathways exist for fish health other than dilution alone. I am not a scientist but I use scientific methods each day to improve the quality of my fabricated products. I employed these same methods way back as a dental laboratory technician. Our dentist customers required repeatable results for success in their practice so we employed science and observation to provide the necessary results in our laboratory.

I'll repeat something I said early in my first post in this thread after reading some of the early posts:

"I feel compelled to say something because,while most readers have already made their decision, some are new to the hobby and may still be trying to make up their mind."

I think the ensuing discussion confirmed that statement. If anything, I feel more firm in my convictions now than I did several days ago, and I'm sure you will say the same.

In the future

If i get the question:

"Are quarantine tanks worth the effort?"​

I'll continue to answer yes.

If someone asks "My fish has ich, what should I do?" I'll continue to recommend that QT and treat the fish.

If someone asks
" My fish had ich and died, what should I have done? I'll continue to ask "Did you QT?"

If someone asks should I QT or should I let immunity naturally develop, I'll continue to recommend QT.

And so on and so on.......

My guess, your answers to these questions will also not be any different as a result of this thread.

Oh well, I guess newbies will ask "why did I read this thread? I'm so confused!"

Happy Thanksgiving!!