How To Safely Use Koi Pond Chemicals

Having a pond full of Koi Fish in your backyard or lawn is a very aesthetically appealing add-on to the beauty of your house. Apart from looking beautiful, they are believed to bring good luck to you and are also proven to be therapeutic. These refreshing water bodies need some treatment from time to time or when some condition arises and requires some external koi pond chemicals to do the trick. So it is better to be aware of the safest ways in which you can treat your Koi pond, whenever the need arises.

Using Pond Salt

Pond salt has been used for years to make up for the lack of natural salt produced by the Koi fishes in the winters and to kill pond parasites. One needs to be very careful while using Pond salt to avoid any unwanted outcomes. Here are a few things you should keep in mind.

  • Use pond salt only if your pond has no pond heater.
  • Whenever the season changes again and the temperature begins to rise by the spring season, change out the salt water gradually over a period of a few weeks instead of changing it all at once.
  • The recommended dosage of pond salt to be used is 1 gram of salt per liter of water. Also, the salt should be added to the pond little by little over a period of 3-4 days to ensure better absorption.

Koi Clay

High purity Calcium Montmorillonite clay powder, also commonly known as Koi Clay, has been used for years for adding beneficial minerals and trace elements to the Koi ponds. The Koi Clay has double benefits to the Koi ponds as it also absorbs a large number of toxins along with providing useful minerals. And yet again, there are a few precautions to keep in mind while using Koi clay as well.

  • Before mixing Koi Clay into the pond, mix about ½ to 1 teaspoon of clay into a small container and leave it undisturbed for at least an hour. If the clay attains a mud-like consistency and sticks to the container instead of evenly dispersing, the clay is not pure and shouldn’t be used in your Koi pond.
  • The recommended dosage for Koi clay is one tablespoon of clay per 1000 gallons of water.
  • Do not use Koi clay in excess otherwise, it can result in skin irritations, altered digestion, and other illness to the fish.


As a matter of fact, nobody likes those green patches that we all address as algae, developing here and there in their fish pond. For this very reason, algaecides were brought into practice. But this mighty weapon of a pond treatment needs to be used carefully otherwise the consequences can be fatal for the fishes in the pond.

  • Avoid treating the entire pond using algaecide all at once. The reason is, that when the algae die, oxygen levels in the water get largely depleted, eventually resulting in the fish being killed.
  • If there are too many algae, either switch on the aeration while the pond is being treated with an algaecide, or treat a small section of the pool every few days.

Well, no matter which other chemical there is to use, here are a few general tips to look after while you are treating your Koi Pond with any kind of chemicals.

Examine the problem first

Well, the unsaid rule is the first one. Many times, parasitic problems arise in the Koi pond due to an alteration in water quality and can be simply treated by partial water change. Therefore checking the pH, nitrite, and ammonia levels in the pond water is a good prerequisite before using pond treatments. For further surety about the problem, a microscopic examination of the skin scrape from the pond works really well.

UV filters are not needed here

Nowadays, many of the Koi Ponds are equipped with UV filters primarily because of their sterilizing abilities. But these filters will act as a setback if they are kept on while using a pond chemical. The organic chemicals in the pond treatments get destroyed, or sometimes even become toxic by the UV light’s action, thereby making them ineffective and in some cases, harmful as well in the presence of UV light.

Therefore it is recommended to keep the UV filters off while using pond treatment and even switch them on after 7-10 days of using the treatment.

Oxygen supply is equally important with koi pond chemicals

Generally, the oxygen levels of the pond decline when the pond chemicals are added, more so in warm weather. Koi pond chemicals like algaecides have been reported to cause fish deaths because there was no aeration to make up for the lack of oxygen while using them. Therefore it is advised to increase the aeration in the pond while using pond chemicals and keep the aeration running throughout the course of the treatment.

Minimum 7 days of patience

The pond chemicals need around 7-10 days to have a complete natural breakdown and show effects. Therefore allow the treatment to work for 7-10 days and perform a partial water change afterward. If the problem still persists, only then you should switch to another chemical so that the two chemicals do not react with each other.

Apart from following these precautions, try and keep performing a quality check of your pond water at regular intervals of time to avoid any kind of problems that can arise.