How much do you "trust" a fallow period?

[Jay Hemdal]

We all know the information...but how much do you trust it?

I'm done my 7th week fallow tomorrow....got Velvet. And I'm not gonna lie, I'm extremely nervous to readd fish, to the tank.

Plan this week is to get some FW mollies and convert them to salt - then add them and watch.

Anyone have feedback on fallow periods? Do you go longer, than recommended? Do you trust the process or use test fish??

IMO - the biggest reason for “fallow period failure” is subsequently adding new fish that were not properly quarantined and bring new disease in with them. That makes it look like the fallow period failed, but actually, the new fish carried the disease into a “clean” tank.

There are some diseases that are caused by ubiquitous organisms or falcultative parasites (bacteria and Uronema) that are not controlled by fallow periods.

Properly done, 45 days is long enough at warmer temperatures, but I add another two weeks for safety to take it to 60 days.

Don’t do the Molly trick unless you quaratine them first - there are some diseases that can go from brackish to seawater and some mollies are housed in brackish water before you get them. It is also a “cool idea” bit one that is not backed up by practical study.

 

[MnFish1]

Wouldn't a microbiome test confirm full eradication? I know that's in the early stages and no guarantee test case not fouled but it's a start in that any present means extending that period.

IMHO - the predictive value of a positive test is probably much higher than the predictive value of a negative test. i.e. if they show up positive you (assume) know they are there. If negative it could have been the area sampled.

 

[MnFish1]

Now I'm curious?

I thought it was all positives with mollies?

I know you don't want already SW converted - as they can be more resistant to SW parasites. But my understanding was that FW converts - were the best way to tell, if the parasite was still present.

I just don't want to add nice fish back - and find out the parasites still there.....my biggest fear right now.

See Jays response - which explains my comment. I also was under the impression that mollies don't always show 'all' parasitic diseases. It makes Ich easy to see - but If you read his post, I think you'll see what I was getting at.

 

[GARRIGA]

IMHO - the predictive value of a positive test is probably much higher than the predictive value of a negative test. i.e. if they show up positive you (assume) know they are there. If negative it could have been the area sampled.

That's my point but poorly worded. Like testing during cycle. I'm concerned with seeing ammonia vs not. Therefore seeing pathogens confirms waiting longer although Jay brought up a good point on new fish being the possible culprit of failure and if he thinks 60 days sufficient then perhaps keep it simple and skip the testing. I'd also think keeping the tank at it's upper temperature limit might assist accelerating their life cycle.

 

[GARRIGA]

See Jays response - which explains my comment. I also was under the impression that mollies don't always show 'all' parasitic diseases. It makes Ich easy to see - but If you read his post, I think you'll see what I was getting at.

Mollies are tougher than damsels and although I get the point of using a black fish there's also probably more susceptible and relatively affordable fishes being better guinea pigs but I get it. Cost is a consideration.

Having said that, I'm going to be using black mollies for my tests because they are very cheap, can easily convert to salt and I'll be keeping first tests around 18 ppt or what best matches LFS kept in low salinity copper treated tanks hoping to snatch an infected fish and use that to inoculate and run tests. Unless I find a lab that can sell me different diseases. Latter being optimal. Converting mollies to that salinity was very easy for me and wasn't until salinity rose higher that I noticed stress although short lived.

Another benefit from FW mollies being few pathogens can transfer over. Not sure which but I believe that for the most part just like low salinity kills most SW pathogens then higher salinity kills FW. Still researching that as it might be best to first acclimate to a certain salinity to rid them of FW pathogens then lower them if using lower salinity to treat SW fish and I like the idea of dither fish. Seen it work too often and I believe reduced stress and proper nutrition go a long way.

 

[Rappa]

I was nervous as well. I NEVER EVER want to go through that again... So I waited almost 90 days after Ich/Velvet that broke out when I put a Powder Brown Tang into my display. I was able to set up a QT tank quickly, and saved most of my fish with Copper Power. I now treat every new fish with C-P and General-Cure for 30 days or more in QT before adding them to display. I haven't had so much as a single white dot on any fish since the fallow period. Fallow does work but it does require patience... which is freakin hard!

 

[Rappa]

I forgot to mention, the biggest reason that I went 90 days was that I decided to add new fish to the quarantine tank during the fallow period, which essentially started the QT period over... extending the fallow period due to the QT'ing of new fish that were in the same QT tank as my treated and now healthy display fish. I figured I would use the time to stock up with the fish that were on my wish-list.