Formalin and salt

[Corrie]

I've been reading a little on the internet, and was surprised to find "you can't mix formalin and salt".

But of all things, I wasn't able to find exactly why?

I found vague answers like "it will kill your fish", etc but no specific description of what it is supposed to do or how it will kill your fish.

Frankly, it sounds stupid and just another internet rumor. I've been mixing formalin and salt for all kinds of fish for a long time, and it's my preferred way to treat a lot of things.

Does anyone know what exactly the combination is supposed to do to "kill your fish"?

[suphi]

Other than oxygen depletion from water, there's no other interaction that I'm aware of. Formalin-based drugs are also widely used in marine fish, so it should be ok.

[Corrie]

Thanks suphi, I think I figured it out after doing more reading.
People are using meds that mix formalin and malachite green. It's not the formalin, more than likely they are od'ing the malachite green.

BTW, you made me want to go to Disney!

Corrie

[bluebelly]

Minnesota's department of natural resources published a manual on fish culture and medicine use in the 80's . In the text it says not to use salt with malachite green to treat goldfish, a sometime deadly combination.

[Corrie]

and that it is.

I've been reading some more on the internet, and it is the combination meds. But for some reason, generally people are blaming the formalin and not going with the obvious which is the malachite green.

Problem with the combination meds is you get way too much MG, and not enough formalin to matter.

We stopped using MG for those very reasons. It will kill fish. But we use formalin for everything, salt, fresh, anything.

Thanks BB, I'm going to try and locate that paper. If I had to guess, I would think the salt/MG combo would not only dehydrate the fish, but also put a toxic level of MG into the fish faster. I'm curious to see if they came to any conclusion as to why it is a deadly combo. I'll bet I'm right. ;)

[Corrie]

I looked in all the usual places, and some not so usual, and couldn't find that paper.
I'm sure it's out there, I just can't find it right now.