Fallow periods: Going Fishless

[kosasihkho]

Any updates on the efficacy of the 6 week fallow period to outrun the ich lifecycle when running at over 80.6 F?

Just discovering the anaerobic variable that can prolong ich’s lifecycle. Arg!

Wondering - if I do rigorous weekly mixing of the sand/rocks in a mixed reef - how certain I can be in achieving a fallow period in A) 6 weeks and B) a full 76 days. It seems like there will always be small anaerobic pockets in a reef tank... ceramic biomedia balls for example. Should I garbage those @Humblefish ?

Thanks

I just finish fallow period (6 weeks). I put 3 black molly inside the DT ( for 1 week should be ok, right?). Hope everything will be ok. Now lets wait and see. I will keep you posted

 

[Humblefish]

I just finish fallow period (6 weeks). I put 3 black molly inside the DT ( for 1 week should be ok, right?).

2-4 weeks would be better

 

[GGonzo]

Why a fallow period will sometimes fail

We've all seen claims of ich, velvet, etc. returning after a 76 day fallow period.

Oftentimes, a fallow period failure is due to human error: The sick fish weren't treated long enough or the treatment itself wasn't done properly, cross contamination via wet hands or equipment, aerosol transmission (more info). It is also possible that undiscovered strains of ich (and other diseases) exist; ones with a prolonged life cycle that exceeds what we know to be true from scientific research. However, there is also this possibility to consider:

Dormancy induced by a hypoxic environment in tomonts of Cryptocaryon irritans, a parasitic ciliate of marine teleosts

Highlights from the study:

• This study demonstrates that tomonts of Cryptocaryon irritans become dormant in hypoxic environments.
• Dormant tomonts resume development in oxic environments at any developmental stages.
• We examined tomont viability following variable sequences of oxic and hypoxic conditions.
• Dormancy in hypoxic environments may be key to the autumn outbreaks of cryptocaryoniasis in floating net cages in temperate waters.

So what does this mean for us and our fallow aquariums? Primarily, the study showed that an ich tomont (the "egg stage" which encysts to corals, inverts, rocks, etc.) can go dormant if the protomont crawls into a hypoxic (low oxygen) environment or anaerobic (no oxygen) region of your DT just before encysting. Examples of this include under your sand bed (especially a DSB), inside a non-porous rock, any "no flow" region of a canister or other aquarium filter. The study also demonstrated that once returned to an oxygen rich environment, these once dormant tomonts resumed their development and released theronts (free swimmers which seek out fish to infect.) How long can it take for a dormant tomont in a hypoxic environment to suddenly be exposed to an oxic (oxygen rich) environment? The world may never know?!

So what can you do to eliminate low oxygen areas of your DT during a fallow period?

1. Take any canister or enclosed filters offline, and sterilize them with bleach. Without fish to foul the water, your DT will be fine with just rock/sand for filtration and good water circulation.
2. Speaking of circulation, crank up those pumps for maximum flow & gas exchange throughout the aquarium. (Don't forget to add a pump down in the sump.)
3. Blow out your rocks (using a powerhead) and vacuum the sand during water changes whilst going fallow. This will "stir things up" and provide free oxygen to those areas.

How can I setup my Display Tank to be "hypoxic proof" just in case I ever have to go fallow?

1. Only use filtration with an open top (like a sump), and avoid canister filters and other filters which may contain anaerobic regions. If needed, take these offline if ever having to go fallow.
2. Use just a light layer of sand; the deeper it is the more likely tomonts can get "trapped" down under there.
3. Never have sand out of reach (i.e. under a rock) in case you need to vacuum it during a fallow period.
4. Only use very porous rock which will allow plenty of flow (and oxygen) to pass through.

More information on Marine Ich (Cryptocaryon irritans) can be found here: Marine Ich

My rocks are man made, I assume they are less porous. Should I just be more diligent about blowing them off with a power head during cleaning? I'll be sure to remove any sand underneath them so I can vacuum the sand bed thoroughly.
Also, should I take my skimmer offline and remove my filter socks?

 

[Humblefish]

My rocks are man made, I assume they are less porous. Should I just be more diligent about blowing them off with a power head during cleaning? I'll be sure to remove any sand underneath them so I can vacuum the sand bed thoroughly.
Also, should I take my skimmer offline and remove my filter socks?

No need to take your skimmer offline or remove the filter socks; however I would use a powerhead with a focused nozzle to blow out your rocks periodically during the fallow period.

 

[GGonzo]

No need to take your skimmer offline or remove the filter socks; however I would use a powerhead with a focused nozzle to blow out your rocks periodically during the fallow period.

Just FYI, this is due to an Ich outbreak in my DT.
Thanks for your quick reply and assistance! I appreciate your time

 

[FloridaGator2016]

No need to take your skimmer offline or remove the filter socks; however I would use a powerhead with a focused nozzle to blow out your rocks periodically during the fallow period.

I remember seeing you post about fallow periods at different temperatures. If I had a fish only tank and wanted to run it fallow, I could raise the temperature in the tank to speed it up if i wanted to go past 80.6F? I thought I saw something about 90 degrees for 48 hrs would kill off ich and flukes.

 

[Humblefish]

I remember seeing you post about fallow periods at different temperatures. If I had a fish only tank and wanted to run it fallow, I could raise the temperature in the tank to speed it up if i wanted to go past 80.6F? I thought I saw something about 90 degrees for 48 hrs would kill off ich and flukes.

80.6F for 6 weeks should eliminate all diseases.

86F for 2 weeks will eliminate Ich, and I suspect Velvet as well: New Ich Fallow Period

You'd need to heat the water to 40C/104F for 1 hour to eliminate Ich (see Table 2): FA164/FA164: Cryptocaryon irritans Infections (Marine White Spot Disease) in Fish

However, that temperature would kill most life in your tank (including beneficial bacteria) not to mention what it might do the aquarium seams.

 

[Tamberav]

I remember seeing you post about fallow periods at different temperatures. If I had a fish only tank and wanted to run it fallow, I could raise the temperature in the tank to speed it up if i wanted to go past 80.6F? I thought I saw something about 90 degrees for 48 hrs would kill off ich and flukes.

When my AC broke my tank got to 93 degrees and easily over 90 for several days, maybe even a week. It did not kill off the resident ich or flukes but I had fish in the tank during that time so maybe it is only helpful if fallow to try and super speed up their life cycle.

I did 45 days at 82. I wanted it a bit higher then 80.6 just in case the temp didn't stay 80.6 the entire time or if the measurement of 'off' a bit. So I figured I would play it safe.

I used a turkey baster on the rocks. I had to remove all the rock to catch the fish so I also stirred all the sand vigorously in the entire tank then replaced the rock and continued to stir it every few days along with blasting the rocks throughout the fallow. I already regularly stirred the sand and had a sand sifting goby so my tank was used to dealing with this. I imagine this could be trouble in a old sand bed that is untouched.

Ich did not return so it seemed it was a success.

 

[FloridaGator2016]

80.6F for 6 weeks should eliminate all diseases.

86F for 2 weeks will eliminate Ich, and I suspect Velvet as well: New Ich Fallow Period

You'd need to heat the water to 40C/104F for 1 hour to eliminate Ich (see Table 2): FA164/FA164: Cryptocaryon irritans Infections (Marine White Spot Disease) in Fish

However, that temperature would kill most life in your tank (including beneficial bacteria) not to mention what it might do the aquarium seams.

Okay so 86F would that take care of flukes also?

 

[FloridaGator2016]

When my AC broke my tank got to 93 degrees and easily over 90 for several days, maybe even a week. It did not kill off the resident ich or flukes but I had fish in the tank during that time so maybe it is only helpful if fallow to try and super speed up their life cycle.

I did 45 days at 82. I wanted it a bit higher then 80.6 just in case the temp didn't stay 80.6 the entire time or if the measurement of 'off' a bit. So I figured I would play it safe.

I used a turkey baster on the rocks. I had to remove all the rock to catch the fish so I also stirred all the sand vigorously in the entire tank then replaced the rock and continued to stir it every few days along with blasting the rocks throughout the fallow. I already regularly stirred the sand and had a sand sifting goby so my tank was used to dealing with this. I imagine this could be trouble in a old sand bed that is untouched.

Ich did not return so it seemed it was a success.

I have two mp 60s in the tank do you think having them blast across the rocks would be enough?

 

[Tamberav]

I have two mp 60s in the tank do you think having them blast across the rocks would be enough?

No.. don’t find that poweheads really get the nitty gritty out of the rock.

 

[Humblefish]

Okay so 86F would that take care of flukes also?

No evidence that warmer water speeds up the Monogenean lifecycle, so best to go fallow for 4 weeks for flukes.

 

[FloridaGator2016]

No evidence that warmer water speeds up the Monogenean lifecycle, so best to go fallow for 4 weeks for flukes.

Okay so 30 days at 86F should cover me for Flukes and Ich. I do have a horn shark and zebra eel. I was going to find CP and treat them with that. If I have two tanks do I treat for 14days and move like with copper or is it a straight 10 days then I'm done?

 

[Humblefish]

Okay so 30 days at 86F should cover me for Flukes and Ich. I do have a horn shark and zebra eel. I was going to find CP and treat them with that. If I have two tanks do I treat for 14days and move like with copper or is it a straight 10 days then I'm done?

I would treat with Chloroquine for 14 days, and then transfer the fish into an observation tank (for further treatments if needed.)

 

[FloridaGator2016]

I would treat with Chloroquine for 14 days, and then transfer the fish into an observation tank (for further treatments if needed.)

Okay that's what I will do then. Should I be worried about the CP going into the plastic if I will be using big rubbermaid tubs Like the one below?

 

[Humblefish]

Okay that's what I will do then. Should I be worried about the CP going into the plastic if I will be using big rubbermaid tubs Like the one below?

Possibly. There is this older study regarding Chloroquine binding to plastic:

 

[Humblefish]

I've never used Chloroquine in a plastic tub, but we didn't notice any absorption when using plastic water pumps + powerfilters back when I was sending water samples off to a chemist to be tested.

 

[FloridaGator2016]

I've never used Chloroquine in a plastic tub, but we didn't notice any absorption when using plastic water pumps + powerfilters back when I was sending water samples off to a chemist to be tested.

Okay I was going to do a weekly water change anyway so I'm sure it shouldn't be much if any. Last thing, Did i read correctly that when using CP you shouldn't have any light get into the tank? like not even natural light?

 

[Humblefish]

Did i read correctly that when using CP you shouldn't have any light get into the tank? like not even natural light?

Exposure to light only breaks down the powder, not once it is dosed in water.

That being said, I typically only use ambient light (to reduce stress) when quarantining fish. I turn on an aquarium light once a day to look the fish over and whenever I feed.

 

[FloridaGator2016]

Exposure to light only breaks down the powder, not once it is dosed in water.

That being said, I typically only use ambient light (to reduce stress) when quarantining fish. I turn on an aquarium light once a day to look the fish over and whenever I feed.

Would you rather run FALLOW for the 2-4 weeks at 80.6 /86 or just take everything out of the FOWLR tank and dry it all out? Debating what to do