It's all @Paul B's fault... my journey to an immune reef (hopefully!)

[Brew12]

@Brew12 - Google "Does freezing kill bacteria". You might find it interesting. In fact freezing in general doesn't kill pathogens, it doesn't kill yoghurt or kefir cultures.

Let's be clear on this. Freezing doesn't kill all bacteria, but it does kill more than half on the first freeze. Here is a study on repetitive freezing including the bacteria type LRS uses.
http://jb.asm.org/content/70/6/711.full.pdf

And I went to an old conversation with Larry and pulled this out.

 

[Brew12]

I read the first article for about 15 minutes searching for something that relates to this discussion - I didn't find any.

I'd suggest reading a little closer then. How is gut bacteria processing algae to directly reduce parasite numbers not related to this discussion?

"Among the dietary additives important for sea lice control are glucosinolates, When these plant derived-phytochemicals are metabolised by fish intestinal microbiota to isthiocynates, they can generate anti-inflammatory responses and promote antioxidant status and detoxification, but they may also promote pro-inflammatory responses in species such as mice. Diets containing glucosinolates were shown to reduce sea lice burden by up to 25% in comparison to control diets (Jodaa Holm et al., 2016)."

Don't take this the wrong way - but Im not going to waste my time reading multiple scientific articles.

I think this says it all. Do you really have interest in learning? You aren't going to take the time to read the science behind it, and you don't accept anecdotal evidence. What is it you would accept then?

 

[Mark]

Here is another snippet by "Pet Med" on "How a Fishes Immune System Works. "
It is a very basic article but may be appropriate here :

All fish have an immune system to fight diseases, although the system is by no means as advanced as the ones found in mammals. The system breaks down into two main parts: protection from physical invasion and internal pathogen handling.

Paul, I don't disagree with your approach or the fish's response. As my post indicated and my future plans. But I guess I have issue with the term immune to a parasite.

My 75G Jaubert Plenum and 30G EcoSystem Mud/Macro filter has been set up for 25 years. At 10 years mature, a loss of power stressed the system with resulting Ich epidemic. The 1500G system had zero addittions for over two years. Not being a micro biologist, I am not going to get into details of how. As a Marine Engineer, I understand logic, as well as, cause & effect.

I think ich can persist in systems but over time cannot sustain large densities, and I think over time may vanish. I think if your tank had gone fallow for 3 months and no introductions of any coral/rock/sand/fish occured, there would not have been an ich outbreak during a stress event. I had those circumstances, and had several major stress events. No ich. But!... the problem I have with the fallow/eradication approach is that it is unreasonable to a hobbyist to quarantine live sand/rock/corals/inverts for 3 months to avoid re-introduction. So I think the "management" approach that folks here advocate makes more sense. Again I don't like the term immune reef.

 

[Subsea]

Paul, I don't disagree with your approach or the fish's response. As my post indicated and my future plans. But I guess I have issue with the term immune to a parasite.



I think ich can persist in systems but over time cannot sustain large densities, and I think over time may vanish. I think if your tank had gone fallow for 3 months and no introductions of any coral/rock/sand/fish occured, there would not have been an ich outbreak during a stress event. I had those circumstances, and had several major stress events. No ich. But!... the problem I have with the fallow/eradication approach is that it is unreasonable to a hobbyist to quarantine live sand/rock/corals/inverts for 3 months to avoid re-introduction. So I think the "management" approach that folks here advocate makes more sense. Again I don't like the term immune reef.

I agree 100% with what you said. I should point out that “over time may vanish” is indicative of the same issue I have with the research papers use of the phrase, “most will hatch”.

 

[mta_morrow]

I agree 100% with what you said. I should point out that “over time may vanish” is indicative of the same issue I have with the research papers use of the phrase, “most will hatch”.

You must have a heck of a time with weather forecasts![emoji33]

 

[kirstyflash]

This thread is full of all sorts of innuendos...

Oh dang! Where are the innuendos? I missed them skimming thru the bull ****! But not you Paul B, love your work, follow your threads. I prefer myself as a lurker but just have to ask...Is this back on topic yet? I was really curious on the processes and outcome.

 

[Subsea]

@Mark
I suspect that the reason your stress event did not show ich on your fish was because Ich was never in your tank. In my 1500G system during a 10 year period, Ich got in and was dormant. Your 3 month fallow rule is not absolute with respect to Ich. I suspect it is far from absolute on many other things with respect to dormant life forms.

Just some thoughts about the absolute effectiveness of quarantine.
Laissez les bonne temps roulee,
Patrick

 

[Brew12]

But I guess I have issue with the term immune to a parasite.

I'm not sure why, the scientific community uses the term regularly.
https://edis.ifas.ufl.edu/fa164

It's a great read, but here part of the immunity section.
"Fish that survive a Cryptocaryon infection develop immunity, which can prevent significant disease for up to 6 months (Burgess 1992; Burgess and Matthews 1995). However, these survivors may act as carriers and provide a reservoir for future outbreaks (Colorni and Burgess 1997)."

 

[Mark]

@Subsea,

I definitely had ich before the fallow events. I've had run ins with cryptocaryon since my first marine tank in 1990. But I'll give a recap of the fallow timelines.

2007: Did not quarantine fish, brought in a kole tang that introduced ich. At this point I followed the fallow method and had my fish in a separate tank running hyposaline for 3 months. At the time, ATJ in Australia was a great resource and expert in the fish diseases forum on another site. His site is a bit dated and I think he left the hobby, but still a great resource: http://atj.net.au/marineaquaria/marineich.html

2007-2013: Ich free. During this 'era', I quarantined all fish. My prophylactic treatment was hypo/CP/Prazi. I never had ich outbreaks after in the tank. I should mention I had a tough few years at work, long hours. And became a dad. So I didn't really buy stuff for the tank. There were not a lot of vectors for ich to come back. It pretty much ran as is. If I did get a coral, I would detach from plug. I had my share of stress events. Heater nukes, tank move, ice storm power outage/temp drop, etc. My ich magnet tangs stayed clean.

2013: After not replenishing my cleanup crew for more than 6 years, I felt some snails would be a good addition. Literally days later, I had ich. Fish were removed and placed in my 40 gallon q-tank for 3 months. Tank was run fallow with slightly elevated temps. 3 months later, fish went back in... No sign of ich after for 3 years.

2013-2018: No ich. During these years, I replaced the tank with a new system. No new rock or inverts. The tank was reaching the 15 year mark and the silicone looked ragged. I also wanted to go a little bigger. During the transfer I had bacterial blooms and a heater malfunction. No ich.

2018: We have plans to redo our flooring where the tank is. It was decided to move the system to the basement. Like many on this thread, I like diversity. The fact that I'm not one to add new things to my tank a lot had taken it's toll on diversity. I decided to add live sand and some fresh rocks from Tampa Bay Saltwater. I felt this would be a good kickstart to replenish bacteria and microorganism diversity. Days after adding, my ich magnet tangs had ich.... The hepatus tang had it the worst. At this point, I feel like I cannot sustain a practice of going fallow each time or isolating any rock/sand/invert/coral from fish for 3 months. Instead of eradicating like in the past, I will go management route(UV + good feeding habits). I'll update the thread on how it goes.

Based on my history above, I think you can 'eliminate' ich. I think fallow for 3 months is highly effective. It worked twice for me, with long spans of no ich after. This exceeds the recommended 8-10 weeks. But unless you don't plan to add more livestock or plan to isolate every living organism for 3 months(you can't treat inverts prophylactically), it's a losing battle. Isolating coral/snails in a small fishless tank is somewhat practical. Isolating live rock and sand isn't.

 

[Subsea]

@Mark
Thank you for those details.

I have a question about the Tangs getting ich in 2018 because of introduction of live sand from TBS. I would assume that no stress event occurred coinciding with introduction of ich in sand.

PS. The reason I ask is because it seems as if your fish have weak immune systems.

I have had Hippo Tangs in a 75G system for several years, upon an introduction of several small ich infested Hippos, the symptoms cleared up on introduced fish and the Hippo resident never showed symptoms.
Some background:
This 75G tank had been set up for 25/years and had seen Ich at year ten. Tank never went fallow. Six small Hippo Tangs came from Divers Den (90 day quarantine) with three near death as evaluated by gill respiration rates and color of fish. Ich was obvious on these three fish. Because I considered my tank as the most stress free environment available at that time, I choose to release them in this display tank. Established Hippo, never showed symptoms. Ich infected fish showed ich for 3 days and persisted with scratching for 7 days, afterwhich all symptoms disappeared in this tank. Do I have dormant ich in my 25 year old tank? I am fairly sure that ich is alive and well in my tank today, five years later.

 

[Lasse]

No matter how great you feed your fish or how great the environment is there is always the risk of adding a pathogen that could decimate a closed system like an aquarium. Fish are a living organism on the planet earth and the last time I checked perfect health in any creature is non existent no matter how great the diet or diverse the environment. It is for this reason I recommend at least having something in place to at least observe new fish before you add them to your main population. This is just common sense. I’ll bet you guys who recommend the non qt would never allow a diseased person into your house. Especially if they were showing symptoms regardless at to how healthy you were. By observing you increase your odds you won’t add something your fish can’t fight off. I’ll garantee your fish are not somehow immune to every disease or parasite because of your methods. To say so is just absurd. It goes against every biological system on this planet. At least by qt’ing new fish you can treat potential problems before they get into the main population. Just because I say quarantine I don’t mean inundate it with copper straight away as you make it sound. Copper is one possibility if a disease is seen but observation is the key point. To recommend anything but is just reckless and doesn’t make sense.

Main question is what the probability that you get an obligate pathogen with your purchase compared with the probability you activate a facultative pathogen because of stress when you use a strict QT protocol. IMO the stress factor is the most important key in order to understand diseases in fish.

If you have working tank and place the newcomers there for a while - it is one thing - but a strict QT protocol include total new start during sterile conditions for every batch of fishes you want to pass the QT. Many strict QT protocols include prophylactic medication too.

Mostly - I do not put my new fishes into the DT directly because of the stress factor. I normally put them in my refugium for 1 to 2 weeks. But it is the same system - no QT and I can´t observe very well there but they get use of my water and will not be attacked of other inhabitants. I have no evidence for this but I believe that the smell of an individual has big importance if the rest of the fishes will see the newcomer as an intruder or not.

I'm not sure why, the scientific community uses the term regularly.
https://edis.ifas.ufl.edu/fa164

It's a great read, but here part of the immunity section.
"Fish that survive a Cryptocaryon infection develop immunity, which can prevent significant disease for up to 6 months (Burgess 1992; Burgess and Matthews 1995). However, these survivors may act as carriers and provide a reservoir for future outbreaks (Colorni and Burgess 1997)."

I found that article too and there is more like that and ongoing work with finding a vaccine.

In general - there is always organism not following the normal protocol - it is a sort of gene diversity that ensure the species survival under changing environmental factors. I´m not surprised at all that people can get an outbreak after 2 years when stressfull situation occur. IMO - you can´t never ever guaranty that your existing system (or fishes) is free from pathogenic organisms. Many people have managed to have a fish in QT for the whole QT-period and when introduced to the DT, it gets sick.

When handling African Chiclids I found out that if I get a sick fish and place it alone for medication in an own aquaria - they died very fast. With adding a couple of friendly fishes - survival rate increase a lot. IMO - a lonely fish used of other fishes around him/her will be in a stress situation because it thinks that there is a danger because the others must have seek shelter. The experience is true - higher survival rate - if the explanation is true - not a clue but it is possible.

Sincerely Lasse

 

[Mark]

@Mark
Thank you for those details.

I have a question about the Tangs getting ich in 2018 because of introduction of live sand from TBS. I would assume that no stress event occurred coinciding with introduction of ich in sand.

Some stress likely. Fortunately, it was not a true move of the existing tank. My existing tank would not fit where I needed it to in the basement, so I went with a new tank of different dimmensions. I set up the new basement system while the existing tank was still running upstairs. Once the rock and sand were added and water quality/biology looked good(2 weeks), I started transferring fish and coral over several days. That was certainly stressful, but at least they were moving from one system to another(versus temporary holding tanks if I had moved the existing tank). That said, I've had worse stress events prior, so my gut is telling me the ich came with the rock and sand. The ich manifested with just a couple of spots on the tangs, and 2 weeks later the second outbreak was massive. The fish are still alive though, and eating well. I have a UV coming next weekend in the mail, which will be part of the "management" program. I should also add that my clowns, mandarin, and anthias only have 1-2 spots on them.

I'd like to add, I don't fault the TBS rock or sand for this. When you take rock/sand from the ocean and air cargo it a few hours later to your tank, you have to accept good and bad hitch hikers. I was prepared for that. I didn't expect ich, but rather mantis and gorilla crabs. I think long-term, the diversity replenishment will pay off. The crackle and pops from the hitch hiker pistol shrimp have already made it interesting. No regrets!

 

[Mark]

Again, ATJ was a great aquarist and resource. I hope we seem him back in the hobby at some point. I think he's more into diving now. But from his site: http://atj.net.au/marineaquaria/marineich.html

"Burgess and Matthews (1995) demonstrated acquired immunity in the thick-lipped mullet, Chelon labrosus. They found that 82% of fish that had been previously exposed to high levels of theronts were immune to a secondary exposure.
....

Burgess and Matthews (1994) were attempting to maintain a viable population of C. irritans which could be used in later studies. To maintain the parasite populations, they needed host fish in order for the trophonts to feed and continue the life cycle. Each host fish was only used once in a process of serial transition such that none of the hosts would die or develop an immunity. While the procedure worked very well and enabled them to maintain populations for some time, the viability of the populations decreased with time and none of the 7 isolates they used survived more than 34 cycles, around 10 to 11 months. They suggest this is due to senescence and aging in cell lines is well recognised in Ciliophora.

The presence of aging cell lines in C. irritans suggests that an aquarium that has been running for longer than 12 months without any additions is unlikely to have any surviving "Ich" parasites, yet another exception to "Ich" always being present."

It's interesting that they had to use fish only once, to avoid acquired immunity, to maintain a viable population of ich. I still don't like that immunity term, I think resistance is better. But I guess it doesn't matter.

 

[WVNed]

30 years ago the diatom filter was state of the art.

It was considered a chemical free way to treat ick and was used by people breeding fish.
It uses an inert media that can trap the free swimming parasites.
There was a protocol you had to follow and it disrupted the life cycle of the parasites like TTM does we used to treat a badly infected fish. If I remember right I also used malachite green which was to aid in healing the damage the ick did to the fish and prevent bacterial infection.
My father in law had one and bred plecostomus and I raised cichlids.

It seems it would be perfect for the problems this thread is about.

Why has it fallen out of favor?

 

[Paul B]

LOL

Vendetta

Pseudoscience VS experience.

all polite like.

. But I guess I have issue with the term immune to a parasite.

Mark maybe I should have said "my" fish are, or seem to be immune at least for 35 or so years. I can't say they are almost immune because that would suggest that there was one or more times when I lost a fish in that time from a parasite. But I didn't so I "assume" they are "totally" immune from at least any parasites I added. I don't know if the parasites from New York water can infect tropical fish. I don't see why not because our water here now is about 70 degrees. I also can't swear that all the fish I added in 35 years from dozens of stores and different people's tanks and the fish I collected were infected but it seems to be a good assumption. The disease threads are full of people adding one coral or clam and immediately their fish are infected.
I am almost 70 years old. If I keep the tank running for another 15 years (probably in a nursing home) and if nothing gets infected would that be enough time to say my fish are immune or would the tank have to run 100 years?

Most of the people here are Noobs to me and they have been trying to discredit my methods for decades. But even if my methods are ridiculous and can't possibly work, why do they. Where are the methods from people who quarantine and have fish that are only dying from old age while spawning that entire time. This hobby is 47 years old in the US, where are the old tanks? What happened to those fish? I know because I have been here all that time and almost none of the people from the beginning of the hobby or even 20 years ago got out of the hobby, Or died.

I didn't wake up one day and come up with this. I have researched this for 50 years and learned by doing. Most people learn on the internet which is by following. Following is great but if you never leave the box and try something else you just won't know and you will use the same methods we used in the 70s which didn't work then and don
t work now. I have been mis quoted so many times in this thread that my head is spinning and it is giving me a headache. Can you count how many times I said "all bacteria is not the same, Only disease causing bacteria will get fish immune" Then 5 people will say "there is bacteria in everything. That has nothing to do with what I said. Also quarantine kills fish. No, it doesn't right away, but it does as soon as a pathogen is introduced. Quarantine is keeping fish away from pathogens. Not observing them in a tank. People know what I meant. I also didn't say anything about copper killing an immune system. If I did, I was wrong as I just don't know. I am very busy building much of my new house and I come on here for a few minutes to "relax" but I can't choose every word perfectly especially when people know what I mean very well.

I just moved my tank here. Talk about stress with me and the fish. They were in a box in filthy muddy water, I threw them into NSW with no lights, heater, nothing. I lost nothing. If anyone wants to come here and look, be my guest. Bring a sick fish if you like.

 

[Paul B]

Why has it fallen out of favor?

It has not, I used one yesterday

 

[Mark]

30 years ago the diatom filter was state of the art.

It was considered a chemical free way to treat ick and was used by people breeding fish.
It uses an inert media that can trap the free swimming parasites.
There was a protocol you had to follow and it disrupted the life cycle of the parasites like TTM does we used to treat a badly infected fish. If I remember right I also used malachite green which was to aid in healing the damage the ick did to the fish and prevent bacterial infection.
My father in law had one and bred plecostomus and I raised cichlids.

It seems it would be perfect for the problems this thread is about.

Why has it fallen out of favor?

Well, to go one further, skip the diatomaceous earth and just use a 25 micron pleated filter. Theronts are 25-60 microns. A pleated filter alone should remove them quite effectively. That's what the Steinhart aquarium did to get Crypto under control on one of their smaller displays.

 

[MnFish1]

There has been written down many explanations why we do as we do but you do not accept them. Instead you try to criticize every comma like it is a preview for a scientist paper.

I have not say that we know more than others because of age – I´m only mentioned this because I think it interesting that at least 5 persons from different cultures, different backgrounds and because of age have a long experience with living animals in a glass box has come to the same general conclusion. I think we all have going through the different stage of knowledge and experiences by our self and been able to come to some conclusions how to do it. However - because of differences in background – we will explain our conclusions in different way. When Paul B criticize the use of prophylactic treatment of fishes in quarantine protocols – he does it from the outcome – fish die although a straight quarantine protocol is followed. When I criticize the same thing I´m able to do it from a general knowledge of breakdown pathways of foreign substances in an organism’s body. I do not know if Paul B knows about MFO and P-450 enzymes – but I do - and can use this knowledge to state that prophylactic treatment with help of different substances that’s not been developed for fishes are not a very bright idea. It often creates more harm than good in the long run.



Years of experiences - I was going to say 99 % but play safe with 90 %. I can put it upside down - prove that it is not that way that stress play the most important role i diseases in an environment that´s it is the most favourable for many potential pathogenic organisms - namely water.



That´s right - in a scientist point of view immunity is acquired through earlier exposure of the pathogenic organism but on the other hand - there has been shown that fish slime can have a content of active antibodies too.



Yes - but the basic philosophy is the same - a very diverse biological ecosystem including the natural bacterial ecosystem



That´s a false statement Must of us reject the quarantine tank because it is not a stable system and if you build it as a stable system (as Brew12 do) it is not according to the quarantine protocol - you can´t ensure that there is no pathogens left if you do not disinfect the system after every run. A mature system is like try to take a site in a crowded bus - if there is no place - you will be pulled off. An to fill a bus - that can be done quickly.

This lead to the term Probiotic. I do not believe in probiotics at all - because of the crowded bus syndrom. Probiotics can only work if the bus is not crowded. However - to confuse the term probiotic treatment with acquired immunity is totally wrong. They are two different processes.

Paul B:s theories abut the gut flora maybe not so wrong - this has been a ground breaking article Decreased gut microbiota diversity, delayed Bacteroidetes colonization, and reduced Th1 responses in infants delivered by Caesarean section

Sincerely Lasse

I dont know why you quote many of my posts - when most of the things you say I agree with already - and have posted as such.

1. I dont use a quarantine tank. I dont use prophylactic chemicals.
2. I have mentioned several times innate (slime, etc) immunity vs pathogen specific immunity. There is no paper out there on fish immunity that suggests there is not an innate immunity. So of course scientists believe in both immune systems in fish.
3. I also believe in the crowded bus syndrome - which is why adding more bacteria doesn't lead to more diversity. Either the bacteria thats already in the tank overtakes the new bacteria or the old bacteria is overtaken (after the bacteria levels in the tank are high enough to reach carrying capacity).
4. I dont believe that the bacteria levels in live cod fish differ from frozen cod. Either way - just like adding probiotics, most of the eaten bacteria is destroyed - it doesn't remain in the fish.
5. I think that as others and many papers have stated that parasites eventually die off in a tank with immune fish. A big reason for success appears to be extraneous methods that decrease free swimming parasites (ozone, high dose UV, etc etc).

Regarding 'stress' in fish - stress is such a broad term that it becomes almost meaningless. There is also no way to 'prove a negative' - so I can't prove that 99% of fish disease is due to stress. But I would say - that common sense would tell you that though 'stress' plays a role as shown in many papers, you have to have the disease organism present for that disease to be 'caused'.

 

[Mark]

Mark maybe I should have said "my" fish are, or seem to be immune at least for 35 or so years. I can't say they are almost immune because that would suggest that there was one or more times when I lost a fish in that time from a parasite. But I didn't so I "assume" they are "totally" immune from at least any parasites I added. I don't know if the parasites from New York water can infect tropical fish. I don't see why not because our water here now is about 70 degrees. I also can't swear that all the fish I added in 35 years from dozens of stores and different people's tanks and the fish I collected were infected but it seems to be a good assumption. The disease threads are full of people adding one coral or clam and immediately their fish are infected.
I am almost 70 years old. If I keep the tank running for another 15 years (probably in a nursing home) and if nothing gets infected would that be enough time to say my fish are immune or would the tank have to run 100 years?

Most of the people here are Noobs to me and they have been trying to discredit my methods for decades. But even if my methods are ridiculous and can't possibly work, why do they. Where are the methods from people who quarantine and have fish that are only dying from old age while spawning that entire time. This hobby is 47 years old in the US, where are the old tanks? What happened to those fish? I know because I have been here all that time and almost none of the people from the beginning of the hobby or even 20 years ago got out of the hobby, Or died.

I didn't wake up one day and come up with this. I have researched this for 50 years and learned by doing. Most people learn on the internet which is by following. Following is great but if you never leave the box and try something else you just won't know and you will use the same methods we used in the 70s which didn't work then and don
t work now. I have been mis quoted so many times in this thread that my head is spinning and it is giving me a headache. Can you count how many times I said "all bacteria is not the same, Only disease causing bacteria will get fish immune" Then 5 people will say "there is bacteria in everything. That has nothing to do with what I said. Also quarantine kills fish. No, it doesn't right away, but it does as soon as a pathogen is introduced. Quarantine is keeping fish away from pathogens. Not observing them in a tank. People know what I meant. I also didn't say anything about copper killing an immune system. If I did, I was wrong as I just don't know. I am very busy building much of my new house and I come on here for a few minutes to "relax" but I can't choose every word perfectly especially when people know what I mean very well.

I just moved my tank here. Talk about stress with me and the fish. They were in a box in filthy muddy water, I threw them into NSW with no lights, heater, nothing. I lost nothing. If anyone wants to come here and look, be my guest. Bring a sick fish if you like.

Like I said, it doesn't matter really.. Immune or resistant or whatever term. I hope the rest of your post was not directed at me. If you look at my posts, you'll see that I agree with your approach. I am not discrediting anything. I also quoted Burgess who made an assessment about fish becoming "immune" to ich after a few infestations. We're on the same side.

 

[MnFish1]

The water gets deep fast on this thread. I read the first post and I read the last page.

Recently, I read a scientific article which documented that 65% of fish died to stress as opposed to 19% due to pathogens.

My 75G Jaubert Plenum and 30G EcoSystem Mud/Macro filter has been set up for 25 years. At 10 years mature, a loss of power stressed the system with resulting Ich epidemic. The 1500G system had zero addittions for over two years. Not being a micro biologist, I am not going to get into details of how. As a Marine Engineer, I understand logic, as well as, cause & effect.

Because I observed Ich in a system with no introductions for > 2yrs, it is only logical to observe that the
28 day incubation of Ich cysts is not absolute. Forty years ago, scientific literature said 14 day incubation period. Today, depending on who you read, incubation period for Ich is 28-56 days. Because of the large changes in incubation period, I decided to go deeper into reading what research papers actually said. The first three peer reviewed research papers said, “most will hatch in X amount of days”. The word MOST says it all. Most does not mean all. Some don’t hatch “right away”. So when do they hatch.

There is also the fact that fish can be intermittently 'Infected' at very low levels without any evidence of disease. This keeps the disease 'In the tank' even though you can't see it. There is also a great deal of evidence that if you decrease the numbers of parasites with UV/Ozone/microfiltration, that the levels of parasites can drop to the point that they can no longer maintain a population.

PS - the longest time that CI cysts have lasted is 76 days (not to say it might not be longer) - but that is the reason people leave their tanks 'fallow' for 76 days. There has never been a documented (key word documented) episode where cysts have survived/been infective longer than 76 days.