tang disaster

breakout

New member
Hello:

I just had a yellow tang croak after two days in my quarantine. The SG was 1.012, PH 8.2, 0 NO3, NH4, and NO2. There is an Aquaclear HOB with 4 biostars from my Display tank and a powerhead in my 29 hospital tank. Any thoughts where I went wrong? I drip acclimated the fish to my new salinity. I checked on him before bed and he was fine. This morning...an ex tang.:sad1:
 
I was trying to perform a hyposalinity treatment to destroy any potential cryptocaryon iritans bugs hiding out.
 
What was the specific gravity he came from? (btw, 1.012 is specific gravity salinity is in ppt )
 
It takes several days to acclimate a tang to the SG. That is how it is describe in the hypo treatment. Thanks

Steffen Sparks
 
Hmmm... I definitely [profanity] that up. I was under the impression that it wasn't that tough on them to go down in sg.
 
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I disagree. Changing specific gravity is not the same stressor going up versus going down. The physiological difference to the fish is huge. When I worked for a previous public aquarium (I don't use hypo now - for other reasons). We would routinely take fish from 1.022 to 1.014 as fast as we could change the water in the tank (about an hour). On the other hand; going from 1.014 to 1.022 would be done over a period of DAYS.

That said, it is entirely possible that your fish had compromised kidney/gill function, and that can certainly cause issues, but is readily identifiable; did your dead tang look all "fat and sassy" after it died, even more plump than when you bought it? If so, it was showing edema, and indeed, the drop in S.G. was the culprit. On the other hand, if the thickness of the fish was the same, then the fish's kidney's were able to handle the change.

Botched drip acclimation kills more fish than most people realize. Taking too long, not using aeration, letting the fish get stressed in a plain white styro are all common problems. Virtually nobody understands that the drip rate (actually a flow rate) needs to increase during the process in order for the percent change to remain constant.

Jay
 
I disagree. Changing specific gravity is not the same stressor going up versus going down. The physiological difference to the fish is huge. When I worked for a previous public aquarium (I don't use hypo now - for other reasons). We would routinely take fish from 1.022 to 1.014 as fast as we could change the water in the tank (about an hour). On the other hand; going from 1.014 to 1.022 would be done over a period of DAYS.

That said, it is entirely possible that your fish had compromised kidney/gill function, and that can certainly cause issues, but is readily identifiable; did your dead tang look all "fat and sassy" after it died, even more plump than when you bought it? If so, it was showing edema, and indeed, the drop in S.G. was the culprit. On the other hand, if the thickness of the fish was the same, then the fish's kidney's were able to handle the change.

Botched drip acclimation kills more fish than most people realize. Taking too long, not using aeration, letting the fish get stressed in a plain white styro are all common problems. Virtually nobody understands that the drip rate (actually a flow rate) needs to increase during the process in order for the percent change to remain constant.

Jay

Agreed. Otherwise freshwater dips will also kill fish (which is doesnt).
 
Agreed. Otherwise freshwater dips will also kill fish (which is doesnt).

Here is the keyword in your statement. A freshwater dip for a few minutes wont kill them usually, leave them in freshwater and let us know the result. You cant just drip acclimate a fish to a salinity consistent with hypo, which mind you is to be 1.009-.010 if you want to kill marine ich.
 
Here is the keyword in your statement. A freshwater dip for a few minutes wont kill them usually, leave them in freshwater and let us know the result. You cant just drip acclimate a fish to a salinity consistent with hypo, which mind you is to be 1.009-.010 if you want to kill marine ich.

??? I never said that straight freshwater wouldnt cause them harm. The claims have been that the salinity was brought down TOO FAST. In which case, a FW DIP would be WAY faster, and cause more death.:uzi:
 
Fish have short term coping mechanisms to deal with rapid salinity changes. Once that salinity change is too drastic(re: far too long to compensate) for their coping mechanisms, they die. There is a reason why the term acclimation even exists.
 
Fish have short term coping mechanisms to deal with rapid salinity changes. Once that salinity change is too drastic(re: far too long to compensate) for their coping mechanisms, they die. There is a reason why the term acclimation even exists.

Im sorry, I dont understanding what you are talking about. The suggestions on the posts above referred that he had dropped salinity too fast, which caused a fish death. I said, "if this were the case, FW dips would also kill a fish". I dont deny (nor never have) that long term hyposalinity will cause issues.

I think we are saying the same thing, but dont understand why you disagreed with my first statement.

FWIW, I argued long and hard on this exact topic (that hyposalinity WOULD indeed cause negative impact on marine teleosts), and was asked to provide references, and despite my best searching, I couldnt find any. While it is totally logical to me, I couldnt empirically show it.
 
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Fish have short term coping mechanisms to deal with rapid salinity changes. Once that salinity change is too drastic(re: far too long to compensate) for their coping mechanisms, they die. There is a reason why the term acclimation even exists.

Also, FWIW, what is this "short term coping machanism" you are talking about? I dont think they do at all. I just think it doesnt cause fatal damage until prolonged exposure and effect.
 
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