How To Salt Bath Your Koi

Salt is an excellent tonic for fish, especially when they are behaving strangely such as sulking on the bottom of the pond, which can happen occasionally with fish for lots of various reasons.  Once you have tested your water and observed your koi for any rubbing or flashing (which may require a whole pond treatment  to address parasite issues or other water quality problems) and if it is a single koi that is unwell, a salt bath may just be the solution to get it back fit and healthy; it is important to understand that salt bathing your fish is not the answer to a problem with water quality or a parasite problem in the pond.

Usually a salt bath has at a much higher concentration of salt than what would be safe to maintain in a pond or quarantine tank, and is always a treatment carried out outside the pond.  Never add the below outlined concentration of pond directly to your pond.  Here’s an expert guide to salt bathing your koi, why we do it, when to do it and the process to get it done correctly and safely.

The first thing you will need is a suitable vessel depending on the size of the koi to be bathed; you can either purchase an expensive koi bowl or use something suitable like a plastic storage container, which are far more cost efficient for the task at hand.  As long as the size isn’t too big and isn’t too small, it can be used for salt bathing your fish.

For the example of this exercise, our imaginary koi in need of a salt bath will be 14 inches.  So a suitable vessel has been selected (for our 14″ koi our vessel is going to measure around 20″) and we then add pond water using a bucket; ideally the bucket with have levels marked on the inside with litres/gallons.  Our buckets usually hold around three gallons and will cover a few inches above the top of the fish with one bucket, however you may use a second scoop of water if your bucket doesn’t cover the whole of the fish.  If you have used two buckets of water, you will have around six gallons of water.

We would then add the salt at a recommended dosing level of between 3 and 4 ounces per gallon; the formula would be 3oz salt x 6 gallons of water (2 buckets) = 18oz of salt required.  The type of salt you use for bathing the fish should be 99% pure water softener salt or Pond Salt.  

WARNING: Do not use other household salts or dishwasher tablets as these can be very harmful to your koi!  Also never leave a koi unattended when salt bathing, as if left for too long in a high concentration salt bath, the fish will die from a salt overdose.

Using kitchen scales, measure out the quantity of salt required at 3/4 ounces per gallon, and add to your water, mixing thoroughly BEFORE the koi is added; ensure that there is no salt residue on the bottom as if salt is not fully dissolved it can burn the skin of your koi.  Once all the salt is mixed, you can add a small air stone if you have one (optional) and that is the preparation phase of your salt bath done.  If you are unsure about any of this, always consult with an expert (you can call one of our friendly team who can help).

When you salt bath a koi, we recommend bathing time up to 5 minutes as each koi has a different tolerance levels to the salt.  If the fish starts to lose its equilibrium i.e. rolls over on its side, it would be time to remove it and return to the pond; this time can vary from anything between 30 seconds to the full 5 minutes dependent on the size of the fish and how strong it is. If you bathed a koi at 3ozs per gallon of salt and it did the full 5 mins without a problem and you need to bath again a few days later you may decide to up the salt level on the second bath to say 3.5oz or even 4oz due to the fishes tolerance of the salt levels used. This also works the opposite way. If you used the minimum level of 3oz and the fish only lasted 30 seconds or a few minutes before rolling over, you would return the koi to the pond, but if you need to bath again the dose level would still remain this minimum amount.  It important to know why you are using a certain level of salt fish dependent.

Catching the fish to be bathed is very important; don’t spend half an hour chasing it round the pond, otherwise it can be counter-productive and can cause more stress than the bathing is going to solve, so be careful to spy your chance to catch the individual fish quickly and safely. Once this is done place the fish into the bath and ensure you don’t leave it unattended and have a cover or net ready in case it jumps out, once the fish has settled in the salt bath, obverse it and time how long it’s in the bath, at any point during this process if it losing its balance and starts to roll over, stop and return to the pond. Make a note of what you did and dosing levels used.  This can be the starting point for future salt baths making your process smoother and well organised.

After the salt bath, the water can either be used for another fish whilst it is still mixed, otherwise you may just discard it.  Don’t keep the mix for a few days, if you intend on doing a second salt bath, redo the mix on the same day you bath the fish again.  If after a salt bath, the koi doesn’t pick up in the next couple of days, you can bath it only if necessary every couple of days.  A koi can look fully cured and then slip back to how it was after a few days, for various reasons, in which case it would be worth giving the koi a second bath.

Quick recap

  • Suitable bowel/vessel
  • Bucket with measure
  • Use pond water
  • Correct Salt (3-4 ozs per gallon)
  • Mix thoroughly
  • Air stone
  • Bath up to 5 mins
  • Remove if it rolls over
  • Monitor after bathing
  • Discard bath after use

Hopefully this will add another useful technique to your koi keeping armoury allowing you to keep on top of any issues that arise in your pond.  Please feel free to comment below about your experiences with salt bathing koi or ask any further questions you may have, and as usual share this article with your koi keeping friends whom may find it useful.  Thanks for reading!

  • Apr 19, 2019
  • Category: News
  • Comments: 0
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