Question on salt in freshwater

[Wy Renegade]

First off, a little background info -

I'm an old school freshwater aquariast; I've been keeping multiple tanks for many years. My technology is certainly not current, and I'm trying to catch up on innovations that have occurred in the last few years. 90% of my tanks still run using a simple undergravel filter and powerheads for filtration. I'm trying to read through and gleam what information I can from threads - this of course has generated a few questions.

The first one, is the recommendation I've seen several times not to add any salt to freshwater tanks. When I was taught (many moons ago), I was told to always add 1 tablespoon of aquarium or pickling salt for every five gallons of water. I was told, that just as your body needs NaCl, so do fish or any other living organisms. I was also told to replace that salt every time a water change was done. Yet as I read through the various posts, I've seen several people indicating that no salt should be added to a freshwater aquarium.

Can any one address this form, and explain the reason for the change in thinking?

TIA

 

[adeebm]

I think the salt was added more as a preventative measure. It helps ward against ich and such, and lowers the toxicity of ammonia to fish(slightly). Most water will already have sodium ions and other minerals which the fish do need for osmoregulation. Nowadays, with better filtration methods, there is no need for adding salt. I'm not sure whether it's detrimental.

--Adeeb

 

[Fishguy2727]

These are freshwater fish, long term exposure to elevated salt levels can cause internal problems (kidney damage). In addition, the recommendations of salt are very high. Lake Tanganyika has some of the hardest freshwater on the planet and to mimic this only takes a fraction of the salt dose you mentioned.

 

[Wy Renegade]

I think the salt was added more as a preventative measure. It helps ward against ich and such, and lowers the toxicity of ammonia to fish(slightly). Most water will already have sodium ions and other minerals which the fish do need for osmoregulation. Nowadays, with better filtration methods, there is no need for adding salt. I'm not sure whether it's detrimental.

--Adeeb

These are freshwater fish, long term exposure to elevated salt levels can cause internal problems (kidney damage). In addition, the recommendations of salt are very high. Lake Tanganyika has some of the hardest freshwater on the planet and to mimic this only takes a fraction of the salt dose you mentioned.

Excellent, thank you both for the information.

 

[maxst2]

These are freshwater fish, long term exposure to elevated salt levels can cause internal problems (kidney damage). In addition, the recommendations of salt are very high. Lake Tanganyika has some of the hardest freshwater on the planet and to mimic this only takes a fraction of the salt dose you mentioned.

Then why to water softeners use SALT to soften the water?

 

[Patman]

They don't the salt in the water soft system I had was used to purge/clean the substrate in the main treatment tank, I just put regular salt blocks in a side tank that the main system would use to "wash" itself that water was run through the system then flushed into the drain. The salt was not a part of the actual water treatment, so much as a part of the self cleaning process of the unit.

Patman

 

[maxst2]

ah ha.. i retract that post... I never really knew how one works till i looked it up. haha. google ftw.

 

[Jason7894561230]

I have only used salt once and it was to help rid of ich. Most fish can tolerate a bit of salt but prefer fresh water. But fish like the Bumblebee goby are a brackish fish and like salt in their tank.

 

[jsoong]

Salt is useful for treating diseases ... one of the first thing I use if my goldies gets into trouble.

However, the old school advice on adding salt (in much lower levels than that for disease treatment) was based on the argument that the a fish has a certain salt content internally, and a FW fish normally expends energy to pump water out of its system to maintain that normal salt concentration. <A SW fish does the opposite, it must pump in water or expels salt as a SW fish's internal osmolarity is less than sea water.> The argument goes that if you maintain a little bit of salt in the water, a FW fish will have less of an osmotic gradient between its inside & outside, so doesn't have to work as hard. Aquarium salt is often used as a "tonic" to reduce fish stress for this reason.

I, however, think that if a fish had evolved to live in pure fresh water, then it is artificial to modify its external environment with salt. Even though we think we are doing good, I am not sure if we are really smarter than mother nature! So I think that we should only be using salt only for fish that had evolved in brackish water, or for fish that normally live in very hard water (such as certain cichlids ... although you would be using chchlid salt rather than plain aquarium salt in that case ...)