Should Salt be used in the aquarium or not?

By Ken Thomson

• Should we use salt in our aquariums?
  

• Salt Types
  

• How I use salt

  • For General Dips

  • For Nitrite Poisoning
    

• The salt alternatives

Should we use salt in our aquariums?

This is one of the more controversial subjects i.e. ‘The use of salt in an Aquarium with fresh water fish’.  As these fish never come into contact with salt why do we use salt is the question.

Salt is generally used to treat fresh water fish for a number of ailments. Whether for parasites, internal Bacteria, external bacteria, fungus and nitrite poisoning. The question is, "are these conditions better cured and the fish helped to recovery by salt - or by other medications?"

In my opinion medications work best in most Community tanks. Whereas with salt you have to be careful with which type of fish you have and the type of salt you use.

Salt Types
The type of salt available can be classified into several types:

1. Table salt, which can be iodised or non-iodised, often has additives e.g. iodine, anti-caking agents etc.  These tend to be in very small amounts and in my opinion, at low levels, do no harm. Some iodine is actually beneficial as it help to prevent goitre (= iodine deficiency) in both humans and fish.
   
   Ref: Aquascience Research Group –The use of salt (sodium chloride, NaCI) in freshwater Aquarium or pond.
   
2. Sea salt, is naturally ‘anti-caking’. This form of salt can increase the Hardness of your water if two much is used in the Aquarium.  As little as 5mg/L can be used for Nitrite poisoning and osmotic stress so this should not present a problem. In my experience I believe that Melafix does a better job at relieving osmotic stress than Sea salt.
   
3. Cooking salt. This is usually the purist form of salt and one, which I personally use  -  though do check the label on ANY type of salt you are going to use, for additives that may cause harm.
   
4. Aquarium salt. This is a product that although dearer than any other type of salt.  It is specifically made for aquariums and is recommended for beginners to the Tropical fish hobby. Some of the manufactures do add extra minerals that benefit the fish. Personally I’ve no preference for any make of Aquarium safe salt it’s up to the individual.
   
5. Marine aquarium salt. This is for Marine aquariums only, as it will affect water quality if used in a fresh water aquarium esp re pH, and ion profile.
   
6. Rock salt. In a form that comes from the salt mines or saltpans. This type of salt is not suitable for human use as it can have some impurities. Personally I’d not use this type of salt due to the impurities.
   
7. Water softener salt. This comes in pellets and is a purified form of salt that could be used but tends to be quite costly so not recommended though if you have some there is no reason not to use it in my opinion.

How I use salt

• For General Dips
  
  • I'm coming to the conclusion that for isolated fish Salt dips of 20mg/l is fine. The max time for a salt dip should be 30mins depending on what species of fish to intend to treat this way. It would be preferred to start with a salt dip of around 10mins keeping a close eye on the fish. I personally would only use the salt bath for parasites as a last resort at the moment, as other medications are far more effective. I’ve limited the strength of the salt dip but some fish can take higher concentrations of salt i.e. especially Cichlids (Discus being one).
    
• For Nitrite Poisoning
  
  • On the use of salt for Nitrite poisoning, this is a possibility, but all the fish in the tank have to be tolerant of salt. In my experience certain fish do not tolerate salt well e.g.:

  Cory's,
  Clown Loaches
  Characins(Tetras)
  Rams etc.
  

  • In my experience, 5mg/l is sufficient for treating nitrite poisoning and this and the level of salt should be built up gradually over time. When the problem is over the salt should be removed by water changes as quickly as possible remembering that freshwater fish don’t normally need salt.

Important Warning: If you are unsure if any fish in your tank cant handle salt, don't use it in your tank, use an alternative medication.

The salt alternatives

Now on one hand I have stated that salt can be used for some species of fish, I do feel there are more appropriate alternatives.  Personally I have used the following:

1. For protozoan and fungal diseases in both cold water and tropical fish I tend to use Waterlife’s Protozin or the King British medication for the condition I’m treating. Whitespot, velvet, Neon Tetra disease and skin slime disease.
   
2. For fin-rot, body-rot, ulcerations and wounds I prefer Myxazin by waterlife. Though there are medications available this is just my choice.
   
3. For internal Bacteria, I tend to use Interpet No9 as its easily obtainable.
   
4. For internal Parasites I use Octozin again by Waterlife. This is also good for Dropsy if it’s caught early enough.
   
5. I use Aquaplus+ as a water conditioner and a general tonic. I use Melafix also as a general tonic. Both these treatments help the fish heal and are ok to use with some other medications (Please check with the makers of any Medications if they can be used with these two general medications). This is where I’d use one of these two medications instead of salt if any of the salt intolerant fish were in the aquarium when the aquarium is in the Nitrogen cycle for Nitrite poisoning.

Please remember:
All treatments are of a personal choice and there are other makes and types of medications available which you might want to consider.

Warning: When using any type of medication, you must be VERY CAREFUL, especially if you have Loaches and Coryadoras species in your aquarium. I personally usually use half the makers recommended dose with both these species of fish.

And Finally, If you are unsure of what’s happening to your fish but you think that they are acting strangely do a water change with, conditioned safe water. As this in a lot of cases will help your fish much more than indiscriminately adding medications.

Hope this helps.

Ken Thomson