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

Salt Dipping Discus

By Dougall Stewart BSc.(Hons).

Discus Salt Dip Methodology

Type of salt to use:
The type of salt used should be non-iodized and contain no ‘free flow’ or other additives (e.g. no iodine or sodium ferrocyanide etc.  I have used ‘Freshwater Aquarium Salt’, rock salt and sea salt.  If purchasing non-aquarium salt please read the packaging carefully as current trends show an increase in the use of additives even in natural products such as rock salt (UK).

If new to Salt Dipping
If new to dipping fish a good place to start would be with a 1.5-2% salt solution; for more experienced users I would suggest you start with a 3% solution immediately.  The solution should be made up in a clean bucket or spare (fishless) tank.  Whilst it is preferable to weigh out the correct amount of salt e.g. for a 2% solution one would use 20g of salt per litre of water, the following approximate measure are given for the sake of simplicity.

1 TABLESPOON of salt approximates to 15grams.  Therefore 1 TABLESPOON of salt per litre of water equates to a 1.5% solution

Worked examples (See Table 1 for other strengths):

• If your bucket/tank contains 10 litres of water you would add 13 tablespoons of salt to get an approximate 2% salt solution
• Or - If  you place 3 US gallons of water in a 5 gallon bucket you would add 14½ tablespoons of salt - to get an approximate 2% solution.
• And so on

It is important to ensure that the salt is fully dissolved before placing the fish in the bucket/tank and that the water temperature matches the tank from which the fish are taken.

As you will need to multi-dip throughout the day, place a heater in the tank, if you do not want to have to remake new salt solution each time; personally I make a fresh solution for each dip.

Before you place the fish in the solution please remember that:

• The length of time that you can leave discus in the solution varies greatly from a few seconds to 30 minutes
• 5 minutes would be a reasonable average
• The time they tolerate the dip DECREASES with the number of dips performed in a 24 hour period
• The fish MUST NOT be left unattended
• During the treatment your fish may show some interesting discolouration, do not worry this is short term.

Place the fish into the solution as quickly and as carefully as possible - then observe the fish and its gill beats closely.

Initially, the respiration of the fish will increase substantially, 120 gill beats per minute is not uncommon.  At some point, the fish will keel over on its side  - and it is at this point that the novice should remove the fish and return it to its tank.   If you are confident and experienced in dipping you may want to extend the time that the fish is exposed to the saline solution - I have found it effective to leave the fish in the solution until the gill beats have slowed to around 20 bpm - irrespective of whether the fish has keeled over or not.

Once the fish are returned to their tank they should within a few minutes regain their composure.  If they appear to be in difficulty, the fish can be supported using your hands and then gently pulled backwards through the water at a slow pace - so that water is forced over the gills.

I have dipped 5 times a day for up to 7 days and there has been no lasting negative effect.  It is important that the dips continue until all visible signs of infection are gone.

TABLE 1A

TABLE 1B

Tables 1 A & B give approximate figures for various salt solution concentrations.  It must be remembered that Table B are coarse approximations only.

Important Note:

In regards to salt dipping it may be argued that returning the dipped fish to the tank from which it came is pointless – this is not the case.  Ideally we would want to return the fish to a tank which had been sterilised and which contained 100% fresh (but conditioned) water, with a matured filter.  It is important to remember here, that all we are doing is ‘knocking back’ the population of a ubiquitous organism and promoting the production of copious amounts of slime layer in order that the fish immune system can regain control and management of the problem.  If we must return the fish to the same tank etc. then large water changes with conditioned water, scrupulous tank hygiene and the addition of salt at a rate of 2 table spoons per 10 gallons (assuming that the tank does not contain delicate plants or salt intolerant species) can work wonders – in conjunction with correct salt dipping.

Dougall Stewart BSc (Hons).

Acknowledgements

I wish to thank:

Fred Goodall

for his help in regards developing a salt dip methodology which I consider to be specific to discus and for his time and patience reading this text.