Adding Bag Water To Tank When Adding New Fish

[TwoTankAmin]

No there are not multiple ways to look at this issue. Lets be logical hare. Make 2 lists. List #1 is all the potential benefits of adding the bag water to the tank, List #2 is all the potential porblems and harm that could come from adding the bag water. Then weight the two and see what makes the most sense to you.
 
Not all pathogens are on or inside fish. Many are in the water.  Take ich for example. If you understand the life cycle of this parasite you will easily understand why adding bag water is a really bad idea.
 

 
White spot disease (Ichthyopthirius multifiliis) is caused by a protozoan with a life cycle that includes a free-living stage. Ich grows on a fish --> it falls off and attaches to gravel or tank glass --> it reproduces to MANY parasites --> these swarmers then attach to other fish. If the swarmers do not find a fish host, they die in about 3 days (depending on the water temperature).

 Nope no swarmers in my bags- I know they aren't there even though I cannot see them. I have faith.  And a lot of bacterial diseases and parasites are in the water before they are in/on the fish. but even though I cannot see them either, I know they must not be there because I have faith.
 
Dumping bag water into a tank is a real coin toss, But sooner or later it you do it enough times, it will jump up and bite you. Some folks may get hit fast and others it may take doing it over a number of years before they get hit. But in the end, people who use Q tanks don't lose whole established tanks from new additions or from pouring bag water into their tanks.

 

[Meeresstille]

Yes, that is making quite a lot of sense TwoTankAmin. I really like that "list" idea and wish you could have been there in my corner. What was also surprising was that I'd found German sites on google also recommending not to add the bag water, but after posting those they were being shoved aside with the explanation that they are poorly written or unconvincing.
 
Well, I've learned a few things! Again! So that's a good thing too! 

  

 

[eaglesaquarium]

Well, they are certainly entitled to their opinions.  But, not all opinions are equal.  Some are based on nothing, and others are based on logic.  Logic would dictate that you minimize your exposure risk to introducing trouble to your tank.  When adding new fish, you are already taking a risk... why compound that risk by adding a whole bunch of water that could be full of all kinds of stuff that is potentially dangerous to your fish, inverts, etc? 
 
 
Honestly, I am having a very hard time thinking of any 'pro' to adding the fish with the bag water versus just adding the fish.

 

[fluttermoth]

I've always not worried about the bag water
 
The way it was explained to me (which made sense at the time!) was, "you don't dry the fish off before you add it to the tank, so anything in the water will be on the fish".
 
But this thread has made me think more carefully about it, and I've changed my mind.
 
Thanks everyone

 

[Meeresstille]

Thanks fluttermoth, for posting that!

 

[Meeresstille]

Well, they are certainly entitled to their opinions.  But, not all opinions are equal.  Some are based on nothing, and others are based on logic.  Logic would dictate that you minimize your exposure risk to introducing trouble to your tank.  When adding new fish, you are already taking a risk... why compound that risk by adding a whole bunch of water that could be full of all kinds of stuff that is potentially dangerous to your fish, inverts, etc? 
 
 
Honestly, I am having a very hard time thinking of any 'pro' to adding the fish with the bag water versus just adding the fish.

I agree!  
(although one pro I came up with is that netting the fish may be more stressful to them than letting them swim from the bag into the tank, but that is minor compared to the stress of coping with diseases, possibly having to medicate...well, everything else mentioned above!)

 

[ShinySideUp]

I add my own tank water to the bag, then take a bit out, add water, take a bit out etc until I'm happy the fish will not be too stressed by any changes in water quality. I then lower the bag in to the tank and let the fish swim out. Yes, bag water does go into my tank but 300 ml of water diluted by 640 litres of my own water is a huge dilution indeed. My opinion on parasites? If there are any they are on the fish already.
 
QT? Never done it. I work on the premise that I don't quarantine everyone I meet in the street or at work and I generally survive. My dog wanders through all sorts of rubbish when out and about and I hug my dog, I still survive. I trust my fish have the same resilience when it comes to disease and there are treatments if things go a bit awry. So far, so good. Cavalier? Probably, but then I also ride a motorbike and so far, I've survived that too.

 

[Meeresstille]

Thanks for posting ShinySideUp, it looks like you know the risks involved! 
I've had ich twice in my tank, but that was in the beginning, I was following the procedure advised by the LFS staff.