Epsom Salt vs Aquarium Salt

[Bassmaster360]

Been a little confused about the difference in effects of Epsom Salt (MgSO4) vs Aquarium Salt (NaCl). Both are salts... ionic compounds. I've heard all over the internet that epsom salt draws out excess fluids from fish, and thus used to treat dropsy, bloat, constipation, prolapsed rectum, etc. I've also heard you don't want to use aquarium salt for those same ailments because somehow aquarium salt makes the fish retain more fluids.

In humans, both epsom salt and normal salt (NaCl) relieve constipation by preventing the intestines from drawing out water from your poop, making your poop moist and stimulating bowel movement. Normal salt is used to dehydrate meat for jerky, etc.

Can someone please explain to me why aquarium salt would make fish retain more fluid? Due to reverse osmosis, wouldn't ANY salt... whether or not it's epsom salt or aquarium salt... draw water out of the fish due to the difference in salt concentration inside the fish vs outside the fish? How is there any mechanistic difference between the Mg2+ vs Na+ ions in terms of drawing fluids out of the fish? Perhaps I'm missing some kind of biological reason, such that the body of fish behaves differently with those two ions.

 

[Bassmaster360]

or perhaps it has something to do with the sulfate (SO4 2-) ion vs Cl-? I doubt it though. Pretty sure even in humans, the fluid transfer mechanism is from the cation and not the anion.

 

[tlindsey]

Been a little confused about the difference in effects of Epsom Salt (MgSO4) vs Aquarium Salt (NaCl). Both are salts... ionic compounds. I've heard all over the internet that epsom salt draws out excess fluids from fish, and thus used to treat dropsy, bloat, constipation, prolapsed rectum, etc. I've also heard you don't want to use aquarium salt for those same ailments because somehow aquarium salt makes the fish retain more fluids.

In humans, both epsom salt and normal salt (NaCl) relieve constipation by preventing the intestines from drawing out water from your poop, making your poop moist and stimulating bowel movement. Normal salt is used to dehydrate meat for jerky, etc.

Can someone please explain to me why aquarium salt would make fish retain more fluid? Due to reverse osmosis, wouldn't ANY salt... whether or not it's epsom salt or aquarium salt... draw water out of the fish due to the difference in salt concentration inside the fish vs outside the fish? How is there any mechanistic difference between the Mg2+ vs Na+ ions in terms of drawing fluids out of the fish? Perhaps I'm missing some kind of biological reason, such that the body of fish behaves differently with those two ions.

Welcome aboard
kno4te
duanes
RD.

 

[tlindsey]

This may help https://www.monsterfishkeepers.com/forums/threads/epsom-vs-aquarium-salt.596793/page-2

 

[Bassmaster360]

This may help https://www.monsterfishkeepers.com/forums/threads/epsom-vs-aquarium-salt.596793/page-2

Thanks tlindsey. Not quite, doesn't explain the mechanistic difference. Perhaps the claim that aquarium salt makes freshwater fish retain fluids is a false myth that's been perpetuated?

 

[tlindsey]

Thanks tlindsey. Not quite, doesn't explain the mechanistic difference. Perhaps the claim that aquarium salt makes freshwater fish retain fluids is a false myth that's been perpetuated?

I'm quite sure that one of the members I've tagged will have the answer for you. Hopefully someone will chime in soon.

 

[Bassmaster360]

I'm quite sure that one of the members I've tagged will have the answer for you. Hopefully someone will chime in soon.

Thank you.

 

[kno4te]

Thanks tlindsey. Not quite, doesn't explain the mechanistic difference. Perhaps the claim that aquarium salt makes freshwater fish retain fluids is a false myth that's been perpetuated?

Mg sulfate directly stimulates the intestine tract and is toxic to certain infections so it’s used for bloat/dropsy etc. If I remember right. Salt and mg sulfate in a higher gradient in the water can help to reduce water from the fish. Water will follow osmotically active elements like Salt and Mg sulfate.

 

[Bassmaster360]

Mg sulfate directly stimulates the intestine tract and is toxic to certain infections so it’s used for bloat/dropsy etc. If I remember right. Salt and mg sulfate in a higher gradient in the water can help to reduce water from the fish. Water will follow osmotically active elements like Salt and Mg sulfate.

Thanks kno4te. Normal NaCl salt also stimulates the intestine tract and is toxic to the same infections that MgSO4 is. I totally agree with you about the osmosis statement. I think the conclusion is that both epsom salt and normal aquarium salt do the exact same thing to fish, and that the claim that they do anything different for treating fish ailments is a myth. The only difference I can think of is that you can run your freshwater tank with a bit of aquarium salt all the time while you shouldn't do the same with epsom salt. I think that's because NaCl is naturally more present in freshwater environments and thus more easily tolerated (or actually preferred) than MgSO4. Mg2+ seems to always be a trace ion unlike sodium whether we're talking about in a lake or in the ocean. They're both anti-bacterial, anti-fungal, and anti-parasitic because of osmosis... draw water out of a pathogen and dehydrate it internally.

Unless somebody can provide proof otherwise, I'm going to assume that aquarium salt is equivalent in effect to epsom salt. All this curiousity came up because I have aquarium salt just in case, but I don't have epsom salt, and I was wondering if I should stock up on epsom salt. It's not a problem of money since both are very cheap, but more a matter of practicality of using both salts in a QT/hospital tank situation.

 

[kno4te]

Not sure about nacl directly stimulating the intestinal tract. Don’t believe it does that. We advise the mg sulfate since it does have an affect on hexemita. Which is why it’s used a bit more. This is I regards to the intestinal tract.

The use of chronic salt in aquariums is not frowned upon but there been keepers with ich that didn’t respond to higher doses of salt/heat treatment. It killed all the fish I believe. Suspected of being salt resistant or tolerant.