Using Epsom Salt in fish therapy

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Apr 4, 2012
Northern Colorado, USA
Working on getting this fine tuned so please know it's a work in progress.

If your fish is looking unwell, bloated, constipated, laying around, looks like a scrape from a fight /mating issues, wound from decor, etc., I have found ES can help.

Epsom salt isn't really a salt it is magnesium sulfate. This is an essential element necessary for life.
Here is a bunch of information about how important it is

Important information - please bear with me if you already know this.

Many new aquarists do not know about the nitrification cycle or it's vital importance in a happy aquarium keeping experience.

This Aquarium Advice article (read it asap) offers lots of good advice and explains the nitrification cycle and what a cycled tank is.

The most basic yet crucial part of successful aquarium keeping is the water.

If your fish is not doing well you need to check the water. The water needs to be in tip top A #1 condition. This can help your fish by removing the stress of an unsafe/toxic condition, and the fish's immune system can work on fixing the illness. (Do not forget good food and monitoring!)

Change the water - do pwc's!

So do the water changes and get your water in the safe zone! Do as many as needed until it is safe, your fish depends on you for this!

Often getting the water parameters in order (and cycled tank) will be the help needed for a happy fish life.

If there is still a need for help, another simple process is available. Possibly enabling you to avoid the need for medication**.

Using Epsom Salt (ES) for fish

Read through this for the whole picture, instructions follow.

For illness 1 tablespoon per gallon of tank water treated 7-14 days.

If all seems well, then another week but with 1 teaspoon per gallon of tank water, with reducing the pwc to 50% daily.

If the fish looks great just keep doing pwc and the ES will be removed over time. This is if your fish is in his own tank being treated, resume adequate pwc's for your tank and stocking.

Or if your fish is NOT in their usual home tank, make sure your main tank is in tip top water quality and add your fish back into the display tank. Use the acclimation process to make sure the water is similar enough and keep stress at a minimum. Resume adequate pwc's for your tank and stocking.


Making the Epsom Salt concentrate

We will make a concentrate of Epsom Salts (magnesium sulfate) 2 cups concentrate is usually fine to start out (unless it is a big tank like 55G on up / use a 5G bucket).

This needs to be pure Epsom salt, no oils or fragrances - can be found at the grocery store pharmacy department, or local pharmacy often by first aid products.

Take a cup of hot water and dissolve the ES into the water stirring when the ES is pretty much all melted in, then take either ice cubes or cold/cool water to get to tank temp, you can wait if it is still too hot or add a couple more ice cubes for 2 cups. The amount of water is not critical.

Don't forget - Add dechlorinator!!!

This should be done during your pwc or right after to have best quality water parameters.

Side note - If you are doing this treatment in your display tank, your water changes should have already been done to have the tank water in ideal water parameters with no unsafe levels!
Remove the same amount of water from the tank as you have prepared. (~2cups)

Then add 1/4 of the water ES mix to the tank,
Wait a little while ~4-8 hours add another 1/4 of the water
repeat and the whole amount should be added in the 24 hours.

If the fish looks like it is on death's doorstep, the adding of the ES water can be sped up and I have never had any issues in doing this. (Even the entire amount in an hour with a near dead fish - emergency.)

The idea in adding it over a day is that the changing tank water will be more slow and should be most gentle way to keep less stress for the fish.

Each day do a near to 100% pwc if the tank is smaller. My thoughts are a hospital tank / container is ideal if you have one fish or just a couple with an issue.

If you are treating your tank which is, say 10G /~38L or more then 50% might be fine but test daily, or even more than that if you are having issues with the water landing in an unsafe zone.

ES is good for plants and I haven't ever had any issues using it. Doesn't seem to cause any issues in shrimp or in snails in a FW tank.

Medications should be used if necessary, (I am not a fish doctor :) )

Good clean water with near daily 100% water changes also helps get the fish back on track.

This is a therapeutic additive which can help many fish regain strength and in addition with the water changes allows them to get back to regular daily activity.

Again if at any time you feel you need to use medication that is a decision for you to make.

Usually about the 3rd day you will note a much better condition of your fish or if not any change for the better, using medication should be considered and in the mean time figure out which stores have what you kind you need and how fast you can. obtain it.

This process has helped many fish over the years for me and I have had many people tell me their fish responded well and got better.

Over the years, I have had to use medication in some of my fish, but clean water is #1 and for several other issues this has helped.

It is helpful (from my experiences with fish keeping) for assisting in constipation, minor bloaty issues, and also for scrapes from decor or wounds from fighting. Osmotic regulation.

You can read about lots of studies of what things magnesium is helpful and good for in humans. (IME helps leg cramps like a champ)

Info starts around the top of the 2nd column

**Disclaimer - This is not advice from a fish doctor, please get any advice you may need from a credentialed, trained professional. I am simply a hobbyist, who knows people love their fish, and want to help keep them from dying. And understand fish doctors are few and far between and accessibility can be out of reach financially.
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