What Is Pond Salt and How to Use Pond Salt in Koi Ponds?

Many koi keepers will eventually ask the question: what is pond salt and what is the use of using it in koi ponds. The question of whether you can use salt in koi ponds will arise, and the honest answer is: sometimes you can, sometimes you cannot. It all depends on the situation, the amount, and the proper use of the salt. In the following guide, you will learn what pond salt is, the use of salt in koi ponds, and how to measure the level of salt used in koi ponds without confusion.

What Is Pond Salt and How Is It Different from Table Salt and Aquarium Salt?

Pond salt is simply plain old sodium chloride. It is used because it is the most simple and least likely to cause adverse effects. It must not have added nutrients, such as iodine, which is sometimes used as a nutrient supplement, or anti-caking agents, which prevent the salt from clumping. These additives are useful in table salt, but not in koi ponds. The basic differences between the three are as follows:

• Pond salt: Plain old sodium chloride. No additives. That's it. Used for koi ponds and other water applications.
• Table salt: Has additives. Don't use it. It will hurt your koi.
• Aquarium salt: Also plain old sodium chloride. It is okay, but it is expensive.

Do not use de-icer salt or road salt. These have other additives that you don't want to get into your koi pond.

So if you are planning to add salt to your koi pond care regimen, make sure to pick plain pond salt or clean aquarium salt. Read the label of the salt you are planning to pick. If it contains other ingredients aside from plain salt, do not pick that.

Why Use Salt in My Koi Pond? Understanding Koi Pond Salinity and Safe Levels

"Salt is not a daily vitamin." Salt is more akin to something in the toolbox. It is used when it is needed. It can help in times of stress.

Koi are fresh-water fish. Salt is in their bodies. Water is pushing into the koi through osmosis — water movement through the koi's skin and gills. Salt reduces the pressure. The koi does not have to work so hard to keep the balance.

Some of the more common situations when salt might help koi:

• After moving koi or adding koi to the pond (transport stress)
• During nitrite problems (nitrite is toxic and affects breathing)
• During parasite control programmes (often used in combination)
• After temperature shock in the spring

Now the important part of koi pond salinity — koi pond salinity levels must always be within safe limits.

A safe level of salinity for koi ponds for the beginner: "Acceptable levels of salinity in a koi pond are from 0.1 to 0.5 percent." 

This does not mean koi pond salinity levels must always be running at 0.5 percent. It means it is used during these times. Higher levels of salinity stress plants and can affect the biology of the filters.

You can use salt in your koi pond. You need to know the level of salinity you are aiming for. You also need to know how to test it.

How to Use Pond Salt in Koi Ponds: Dosage, Steps, and Common Mistakes

Step 1: Know Your Pond Volume (Don't Guess)

For salt math to work, your pond volume must be close to correct.

For a rectangular pond:

Length × Width × Average Depth × 7.48 = gallons

If your pond is curved: the best estimate you can make will do. Or you can measure when you refill.

Step 2: Pick Your Target Pond Salinity

For hobby purposes, most salinity levels will work in the lower end of the range. Many hobbyists begin in the range of 0.1% to 0.3% salinity to support life. If in doubt, it is always better to err on the side of caution.

Step 3: Use a Pond Salinity Calculator

A pond salinity calculator (simple dosage calculator) is very helpful in keeping you from making mistakes. You will input your gallons and desired percentage.

Or if you are old school:

• 0.1% = 1 lb of salt per 100 gallons of water
• 0.3% = 3 lb of salt per 100 gallons of water
• 0.5% = 5 lb of salt per 100 gallons of water

These are commonly used koi keeping guidelines. Always verify.

Step 4: Add Salt Slowly and Pre-Dissolve It

Never put a big clump of salt in your pond and then wonder why things are going wrong.

Instead:

1. Take some of your pond water and put it in a bucket.
2. Add salt to the bucket and mix until mostly clear.
3. Pour the salt water into high-circulation areas of the pond.

Step 5: Mix the Pond (Circulation Is Key)

However, it does not spread right away. It may create "hot spots" of high concentration. This is where circulation comes in.

A strong waterfall return helps to keep the pond mixed. So does a strong pump. Mixing the pond water is good for the fish and helps with accuracy.

Step 6: Test, Then Adjust

You will need to get a salinity meter or test strips to do this step. Test the water in a few hours, then again the next day.

Remember:

• Salt does not evaporate.
• When water evaporates, the salt stays.
• So if you add water to your pond to replace the evaporated water, your salinity level will creep up over time.

When Not to Use Salt

There are times when you should not add pond salt to your pond water:

• You have lots of aquatic plants that you want to keep alive.
• You are adding a medicine that says you should not add pond salt.
• You do not know your salinity level because there is already salt in your pond.

Common Mistakes to Avoid

• Adding iodine or other chemicals to your pond with your table salt.
• Adding pond salt without knowing your pond volume.
• Adding pond salt too fast.
• Forgetting that pond salt does stay in your pond.
• Adding too much pond salt because you are worried about something that has yet to happen.

Salt is good to have in your pond at the right time. However, it becomes bad when it becomes a habit.

Conclusion

So, to answer your original question: Can I put salt in my pond? The answer is yes, if you plan to do it right. What is pond salt? Pond salt is plain NaCl with no additives. It is used to help koi fish in times of stress or nitrite problems. What about salinity levels? The salinity level must be measured and kept at the right level for koi fish to survive. What are safe levels of salinity for koi pond water? The salinity level must be between 0.1% to 0.5%. Use a pond salinity calculator, add salt gradually, and then test.

Good circulation is important too. This will help distribute the salt. A waterfall return is a simple device to mix the water. The Poposoap 40W Waterfall Pump Kit will help circulate the water.

READ MORE: 5 Key Elements for Building an Eco Pond.

Frequently Asked Questions

1. Can I Use Salt in Koi Pond Water Permanently?

Generally, no. Salt is best as a short-term solution.

2. Does Salt Damage Pond Plants?

Yes. Many pond plants do not like salt, especially if the concentration is high.

3. I Added Salt to My Pond and Changed My Mind. How Do I Get Rid of It?

Perform partial water changes. Do not change it all at once.

4. How Do I Determine Pond Salinity?

Use a salinity meter or test strips.