45 Day Fallow periods

[Jay Hemdal]

I've been doing some research into the "76 day fallow period". I never heard of that prior to coming to Reef2Reef this past summer. I had always used 32 days as the maximum time for a tomont to remain viable under tropical conditions, and then I would round up to 45 days to help ensure that Neobenedenia was eradicated at the same time.

Turns out that the 1997 article written by Colorni and Burgess just references his PhD thesis which isn't available for review. Then, his co-author Burgess was also the editor for the journal that published it - certainly a conflict of interest! This paper then got referenced by Noga 2010 (he lists 72 days).

Things get a bit murky from there - if you read between the lines, there is some reference to one case at 68 degrees where they found viable tomonts in a xeric culture (no bacteria). Colorni himself seems to doubt his results apply to the real world, saying that at warmer temperatures and in the presence of bacteria, the tomonts probably don't last nearly as long.

I say that at 81 degrees F., 45 days is an appropriate fallow periods for Cryptocaryon, Amyloodinium and Neobenedenia....this coincides well with a 30 day copper treatment followed by two weeks of copper-free observation.

Addendum: I need to clarify, 45 days at 81 degrees is the minimum value, for people who have some compelling reason to move the fish out sooner. Also, fallow periods fail for a number of reasons, not just the length of time the DT was let to go fallow; cross contamination and incomplete treatment of the affected fish are the two common issues. A fallow period of 60 days if the water is below 81 degrees is more prudent.

Jay

 

[lapin]

Good info

 

[Gorgar]

I've been doing some research into the "76 day fallow period". I never heard of that prior to coming to Reef2Reef this past summer. I had always used 32 days as the maximum time for a tomont to remain viable under tropical conditions, and then I would round up to 45 days to help ensure that Neobenedenia was eradicated at the same time.

Turns out that the 1997 article written by Colorni and Burgess just references his PhD thesis which isn't available for review. Then, his co-author Burgess was also the editor for the journal that published it - certainly a conflict of interest! This paper then got referenced by Noga 2010 (he lists 72 days).

Things get a bit murky from there - if you read between the lines, there is some reference to one case at 68 degrees where they found viable tomonts in a xeric culture (no bacteria). Colorni himself seems to doubt his results apply to the real world, saying that at warmer temperatures and in the presence of bacteria, the tomonts probably don't last nearly as long.

I say that at 81 degrees F., 45 days is an appropriate fallow periods for Cryptocaryon, Amyloodinium and Neobenedenia....this coincides well with a 30 day copper treatment followed by two weeks of copper-free observation.


Jay

Is the 30 day copper treatment in the fallow tank or separate hospital tank treating infected/all residents?

 

[Jay Hemdal]

Is the 30 day copper treatment in the fallow tank or separate hospital tank treating infected/all residents?

The presumption is that the copper would be treated in a separate tank, and no treatment for the infected tank that all of the fish came out of. If you treat your main tank with copper at full strength for 30 days, there is no need to have it go fallow.

Jay

 

[Gorgar]

The presumption is that the copper would be treated in a separate tank, and no treatment for the infected tank that all of the fish came out of. If you treat your main tank with copper at full strength for 30 days, there is no need to have it go fallow.

Jay

Okay that's what i thought just wanted to make sure! I'm about to hit day 50ish (?) Of my fallow period and just doing a little more research to see my options and make sure I'm doing it right. Thanks Jay!

Dave

 

[Vette67]

In my own experience, I battled ich for about 2 years. I initially treated all my fish in a hospital tank (copper for 2-3 week) then just let the copper level drop after that naturally, with water changes until putting the fish back in the DT, while leaving my tank fallow for the recommended 72 days. Each time I would do this, within days of returning fish to the DT, spots would reappear. I would tear the tank down, catch the fish, threat with copper in a hospital tank, and let the tank go fallow for increasingly longer amounts of time, over 90 days at a time. Each time, within days of putting fish back in the DT, ich would return. So it seemed to me like even the 72 day number was an underestimation. The last time I let the tank go fallow for 3 months, I also ran 2 - 40w Lifegard UV sterilizers. And after doing that, my fish have not experienced a recurrence of ich in over a year now.

So I don’t know what to think about that 72 day number. It seems like not enough time to me. My fish in the hospital tank showed no signs of ich until I returned them to my DT, and then just about all fish were re-infected within days. So it always appeared like my DT was never fully cleared. So I still recommend waiting longer than 72 days to anyone that runs fallow.

But that was just my experience...

 

[Courtney Aldrich]

I've been doing some research into the "76 day fallow period". I never heard of that prior to coming to Reef2Reef this past summer. I had always used 32 days as the maximum time for a tomont to remain viable under tropical conditions, and then I would round up to 45 days to help ensure that Neobenedenia was eradicated at the same time.

Turns out that the 1997 article written by Colorni and Burgess just references his PhD thesis which isn't available for review. Then, his co-author Burgess was also the editor for the journal that published it - certainly a conflict of interest! This paper then got referenced by Noga 2010 (he lists 72 days).

Things get a bit murky from there - if you read between the lines, there is some reference to one case at 68 degrees where they found viable tomonts in a xeric culture (no bacteria). Colorni himself seems to doubt his results apply to the real world, saying that at warmer temperatures and in the presence of bacteria, the tomonts probably don't last nearly as long.

I say that at 81 degrees F., 45 days is an appropriate fallow periods for Cryptocaryon, Amyloodinium and Neobenedenia....this coincides well with a 30 day copper treatment followed by two weeks of copper-free observation.


Jay

I have attached Burgess' 1992 thesis that describes in great detail all of the experiments. His thesis shows that excystment (time between trophont encystment and theront release) occurs typically between 5-7 days and the maximum time was 24 days (see pages 95-96).

 

[Jay Hemdal]

I have attached Burgess' 1992 thesis that describes in great detail all of the experiments. His thesis shows that excystment (time between trophont encystment and theront release) occurs typically between 5-7 days and the maximum time was 24 days (see pages 95-96).

Thanks, I must have misunderstood - I thought it was Colorni's thesis that had the data in it.

Jay

 

[Jay Hemdal]

I have attached Burgess' 1992 thesis that describes in great detail all of the experiments. His thesis shows that excystment (time between trophont encystment and theront release) occurs typically between 5-7 days and the maximum time was 24 days (see pages 95-96).

I see where the confusion came in. Here is the excerpt from the joint 1997 paper:

The mean duration of C. irritans' life cycle is 1±2 weeks at 24±27 8C (Colorni, 1992). However, some tomonts can prolong their cycle to as long as 10 weeks.

The second statement, about 10 weeks is technically NOT attributed! That makes things even more muddled. I presumed that the 10 week time frame was reported in this:

Colorni, A. (1992) Biology, pathogenesis and ultrastructure of the holotrich ciliate
Cryptocaryon irritans Brown 1951, a parasite of marine ®sh. PhD thesis, Hebrew
University of Jerusalem.

Jay

 

[Billldg]

This is very interesting. I think the biggest issue is that some reefers have gone 76 days and still had Ick and such in their tank. Now was it introduced back thru some sort on means, or was it never gone, that will always be the question. Does temp and such play a role in how long they needed to go fallow, was their tank at 70 degrees, 78 degrees, or 81 degrees? I am sure you, @Jay Hemdal will understand that bacteria will always find a way to survive, its what they do best. This is a very interesting topic and discussion.

 

[PghReef]

This is very interesting. I think the biggest issue is that some reefers have gone 76 days and still had Ick and such in their tank. Now was it introduced back thru some sort on means, or was it never gone, that will always be the question. Does temp and such play a role in how long they needed to go fallow, was their tank at 70 degrees, 78 degrees, or 81 degrees? I am sure you, @Jay Hemdal will understand that bacteria will always find a way to survive, its what they do best. This is a very interesting topic and discussion.

I think there are too many variables to take everyone who had ich reappear at just there word.
Was there any chance of cross contamination?
Any chance the copper treatment was not done appropriately?
Any chance a fish or a piece of a dead fish was left in the DT?

My understanding is that 2 weeks in copper and then letting it dip below therapeutic is in fact a big mistake. I believe you need to treat for either 30days in copper to rid the fish and the aquarium of ich OR treat for 14 days to rid the fish of ich and then transfer said fish to a sterile tank so they can not be reinfected.

 

[Courtney Aldrich]

Thanks, I must have misunderstood - I thought it was Colorni's thesis that had the data in it.

Ja

I see where the confusion came in. Here is the excerpt from the joint 1997 paper:

The mean duration of C. irritans' life cycle is 1±2 weeks at 24±27 8C (Colorni, 1992). However, some tomonts can prolong their cycle to as long as 10 weeks.

The second statement, about 10 weeks is technically NOT attributed! That makes things even more muddled. I presumed that the 10 week time frame was reported in this:

Colorni, A. (1992) Biology, pathogenesis and ultrastructure of the holotrich ciliate
Cryptocaryon irritans Brown 1951, a parasite of marine ®sh. PhD thesis, Hebrew
University of Jerusalem.

Jay

Hi Jay, I don't know the literature at all and am learning as I go along. I guess the most important point is that your first statement challenging the dogma in the field is absolutely correct and supported by the thesis from Burgess, which clearly shows the fallow time for excystation from the tomont stage is significantly shorter than 72 days we have been told to believe. I searched a little more and found another paper by Colorni (attached) where he shows that the tomont stage is actually even less and dependent on the salinity. At low salinities of 25 ppt, tomonts have long incubation periods of 25-28 days; however, at 35 ppt tomonts excysted within only 13 days!

 

[zalick]

Thanks for your summary @Jay Hemdal !

Having the science support a more "accessable" fallow period for reefers will make it more likely they do it.

 

[Jay Hemdal]

Hi Jay, I don't know the literature at all and am learning as I go along. I guess the most important point is that your first statement challenging the dogma in the field is absolutely correct and supported by the thesis from Burgess, which clearly shows the fallow time for excystation from the tomont stage is significantly shorter than 72 days we have been told to believe. I searched a little more and found another paper by Colorni (attached) where he shows that the tomont stage is actually even less and dependent on the salinity. At low salinities of 25 ppt, tomonts have long incubation periods of 25-28 days; however, at 35 ppt tomonts excysted within only 13 days!

Thanks! Interesting paper - I had not seen that before, but it is obvious from just reading the abstract that this paper is where the 9 ppt hyposalinity treatment AND TTM came from!

The timing of the paper is interesting - it was soon after I began working in public aquariums. My curator at the time, Roger Klocek, had obviously read this, as we were taught about hypo and TTM as aquarists (but in the end, we stuck with copper).

I wish I wasn't closing in on retirement and still working 65+ hours per week - so much more to read and learn!


Jay

 

[Fish Care Practitioner]

This is a very interesting discussion since I lost 5/6 fish recently in a outbreak of either itch or velvet. I moved all 6 fish into a 55 g quarantine tank and dosed copper at 0.5 mg. All five fish died in quarantine even though I fastidiously monitored the Cu, NH3, NH4, and NO3. The last fish survived and after 8 weeks went back into the display. I purchased 4 new fish that went thru the same quarantine and then into the display. I then bought a PB Tang who spent 2 weeks in Cu at the store, 2 weeks in Cu in my quarantine, and 2 weeks treated with Prazipro. 3 days after going into the display, he broke out in ich. I literally wanted to cry because now my DT was recolonized with inch.

So now, I’m at a loss but purchased a $750 UV device that I’ll plumb into my tank... but I’m open to advice.

One of the participants mentioned all the variables that can alter results from person to person and he is so correct. Also know that ich can come on coral as a contaminant in the water.

I think what we need is a new up to date scientific controlled study with defined parameters set up to better determine the life cycle of this organism in the aquarium setting (University folk, Companies?) and what variables might be valuable in fighting it (hyposalinity, hypersalinity, temp, etc).

 

[Jay Hemdal]

This is a very interesting discussion since I lost 5/6 fish recently in a outbreak of either itch or velvet. I moved all 6 fish into a 55 g quarantine tank and dosed copper at 0.5 mg. All five fish died in quarantine even though I fastidiously monitored the Cu, NH3, NH4, and NO3. The last fish survived and after 8 weeks went back into the display. I purchased 4 new fish that went thru the same quarantine and then into the display. I then bought a PB Tang who spent 2 weeks in Cu at the store, 2 weeks in Cu in my quarantine, and 2 weeks treated with Prazipro. 3 days after going into the display, he broke out in ich. I literally wanted to cry because now my DT was recolonized with inch.

So now, I’m at a loss but purchased a $750 UV device that I’ll plumb into my tank... but I’m open to advice.

One of the participants mentioned all the variables that can alter results from person to person and he is so correct. Also know that ich can come on coral as a contaminant in the water.

I think what we need is a new up to date scientific controlled study with defined parameters set up to better determine the life cycle of this organism in the aquarium setting (University folk, Companies?) and what variables might be valuable in fighting it (hyposalinity, hypersalinity, temp, etc).

I agree, new testing is needed and true peer reviewed studies need to be produced. Trouble is, there is no money in it, and everything runs on grants now. You may or may not know, but there is no real R&D in aquarium companies - at most it is a single person with some chemistry background, and at worst, the company just repackages old ideas.

Jay

 

[josephxsxn]

I agree, new testing is needed and true peer reviewed studies need to be produced. Trouble is, there is no money in it, and everything runs on grants now.

Jay

Dare I ask what kind of total we would we looking at?

 

[Jay Hemdal]

Dare I ask what kind of total we would we looking at?

I'm not sure, it depends on the size of the study. Mostly, it would be the lab resources to culture the Cryptocaryon. I've only published a few peer reviewed papers - my HLLE paper had a lot of histopathology charges with it and it cost about $7k all told. I wrote a paper on ozone that cost nothing, I used resources already in place, and did the study during my lunch hours (grin).
There are three likely research venues: Tropical Aquaculture Lab in Ruskin Florida (U of Fl extension). Dr. Stamper's lab at Disney or Andrew Rhyne at Rogers Williams. Trouble is, all three of these facilities seem booked up, the only way they would take on additional projects I think is if somebody came to them with soft money.

Jay

 

[Courtney Aldrich]

This is a very interesting discussion since I lost 5/6 fish recently in a outbreak of either itch or velvet. I moved all 6 fish into a 55 g quarantine tank and dosed copper at 0.5 mg. All five fish died in quarantine even though I fastidiously monitored the Cu, NH3, NH4, and NO3. The last fish survived and after 8 weeks went back into the display. I purchased 4 new fish that went thru the same quarantine and then into the display. I then bought a PB Tang who spent 2 weeks in Cu at the store, 2 weeks in Cu in my quarantine, and 2 weeks treated with Prazipro. 3 days after going into the display, he broke out in ich. I literally wanted to cry because now my DT was recolonized with inch.

So now, I’m at a loss but purchased a $750 UV device that I’ll plumb into my tank... but I’m open to advice.

One of the participants mentioned all the variables that can alter results from person to person and he is so correct. Also know that ich can come on coral as a contaminant in the water.

I think what we need is a new up to date scientific controlled study with defined parameters set up to better determine the life cycle of this organism in the aquarium setting (University folk, Companies?) and what variables might be valuable in fighting it (hyposalinity, hypersalinity, temp, etc).

I agree that we need more research. There is a lot of accumulated empirical knowledge, but it would be great to have more controlled studies. The thesis from Burgess that I attached earlier in the thread is pretty nice and does include some really well designed studies. The paper I attached by Colorni above shows that the fallow period is even shorter at typical salinities used in the hobby. I see you just joined and would suggest you go over to: https://humble.fish/community/index.php, if you haven't already to learn more about fish diseases. You say you used 0.5 mg of copper, but this is incomplete information. The preferred dosage for treatment is 2.5 ppm (2.5 mg/L) for 14 days followed by tank transfer for another 14 days or 28 days of copper treatment. It's possible your copper dosage was too low or that C. irritans was copper-resistant. There are other medicines, such as chloroquine that are also highly effective for ich/velvet, but these are hard to obtain right now.

 

[jaxteller007]

In my own experience, I battled ich for about 2 years. I initially treated all my fish in a hospital tank (copper for 2-3 week) then just let the copper level drop after that naturally, with water changes until putting the fish back in the DT, while leaving my tank fallow for the recommended 72 days. Each time I would do this, within days of returning fish to the DT, spots would reappear. I would tear the tank down, catch the fish, threat with copper in a hospital tank, and let the tank go fallow for increasingly longer amounts of time, over 90 days at a time. Each time, within days of putting fish back in the DT, ich would return. So it seemed to me like even the 72 day number was an underestimation. The last time I let the tank go fallow for 3 months, I also ran 2 - 40w Lifegard UV sterilizers. And after doing that, my fish have not experienced a recurrence of ich in over a year now.

So I don’t know what to think about that 72 day number. It seems like not enough time to me. My fish in the hospital tank showed no signs of ich until I returned them to my DT, and then just about all fish were re-infected within days. So it always appeared like my DT was never fully cleared. So I still recommend waiting longer than 72 days to anyone that runs fallow.

But that was just my experience...

Aren't you supposed to treat at the full copper level for 30 days? Could you have not treated the fish long enough?
Also I think it's been said that they parasites can travel a certain distance by air, how far away is your QT tank from your display?
I'm sure @Jay Hemdal could clarify this lol.