Koi Care Basics Blog

What is the optimum Koi pond alkalinity level?

Generally levels of 50-170 are what is recommended although some Koi keepers are keeping their pond levels even higher at around 180. The reason for this is that alkalinity will decrease over time as the good bacteria in your pond consume bicarbonates which slowly decreases alkalinity.

Alkalinity can also be referred to as carbonate hardness or German carbonate hardness. It is the measure of the concentration of the capacity a solution has to neutralize acid without changing pH. It both maintains and controls water pH. Koi pond alkalinity level can be measured in parts per million of calcium carbonate (ppm of CaCO3), milligrams per liter (mg/L), grams per cubic meter or degrees (dKH).

Test kits measure alkalinity as carbonate hardness or dKH and often in degrees of German Hardness (odH).If you want to convert German Hardness to parts per million (ppm) you can simply multiply by 17.

In spite of the fact that that a pH of 7.4 is best for Koi fish it can be a good idea to keep th pH level a little higher. pH levels can crash quite quickly when your alkalinity (KH) begins getting lower than 80 ppm. Since alkalinity is the buffer that helps maintain pH it is important to test it regularly. You may find that it’s better to keep your Koi pond alkalinity level above 100 or 120 pm. It will give you a bit of a buffer zone to help maintain your pH.

There are several ways that you can add alkalinity to your pond. One way to do this is through water changes. This can help introduce new minerals and can also increase alkalinity. However, if you have softer water it’s alkalinity can be less than 80 ppm. You can increase both the pH and KH by adding Arm & Hammer Baking Soda to the water. One third cup of baking soda per 1000 gallons of water will raise the KH level by 25 ppm.

Make sure that you take care not to raise the KH level more than 25 ppm a day. If you do it will cause undue stress to your Koi. An exception to this is if you are losing fish to a pH crash. A pH crash is when the pH level hits 5.5 or lower. In this case you have nothing to lose by adding a bit more baking soda to the water.

Water doesn’t have to have a high pH to have high alkalinity. Alkalinity is related to the dissolved amounts of calcium, magnesium and other compounds in the water. This is why alkalinity tends to be higher in hard water as opposed to soft water.

There are various reasons that Koi pond alkalinity level will decrease over time.

Decreases occur naturally over time due to bacterial action which produces acidic compounds which combine with and decrease alkaline components.

Ponds with fiberglass construction or vinyl liners tend to exhibit a higher decrease in alkalinity over time and might need supplementation to help them maintain proper levels. Alkalinity can be raised by adding calcium carbonate, oyster shells, concrete blocks, egg shells or limestone.

High alkalinity can be prevented by routinely changing out the water if the water you are replenishing with has a lower alkalinity than the pond water.

An established pond usually maintains an equilibrium in it’s pH value if you keep it clean by removing sludge and any organic materials before they have time to decay. Scheduled water change outs (i.e. 10% / week for small ponds, less for larger ponds) can also help maintain proper pH and Koi pond alkalinity level.

You should definitely purchase a test kit and use it on a regular basis!

Alan Deacon
KoiCareBasics.com

Secrets To Successfully Raising Koi Fry

Successfully raising Koi fry begins with Koi eggs. You should make sure your fry raising pond is equipped with air stones or their equivalent as Koi eggs need well aerated water to develop.

Koi Fry

During breeding some Koi keepers will use mechanical filters in their ponds, but this is not the best idea since when they can get sucked into the filter. This can be prevented by placing a fine net around the filter’s water intake. Microscopic food particles can become trapped on the foam around the filter. This attracts the Koi fry to the area and they become drawn into the filter.

You can forget using a filter altogether if you are willing to do frequent water changes. You need to replace approximately 20 percent of the water during the water exchange.

Koi eggs will usually hatch in 3 to 7 days depending on the water temperature. If water temperature is around 20 degrees Celcius (68 degrees Fahrenheit) Koi fry will hatch in about 3 to 4 days. You will know when the eggs are close to hatching because they will take on a special, shiny look.

Next you will be able to see the Koi fry wiggling and moving inside the egg, and a few hours later they will make their escape! Now you are ready to begin raising them.

As soon as the babies have emerged from their eggs they will attach themselves to the sides of the pond. Koi fry are equipped with a sticky pad that makes it possible for them to remain attached this way for 2 to 3 days. Providing plenty of oxygen is as important for raising the fry as it is for keeping the eggs healthy.

After 2 or 3 days of being attached the Koi fry will make their way to the surface of the pond to get some air.
When this occurs air passes into their swim bladder. Afterwards they will be able to swim happily around the pond!

At this point you will need to begin feeding them. Very small Koi fry can be fed newly hatched brine shrimp. Hard boiled egg is also a good choice in the first few days of raising Koi fry.

If you can’t provide them with this you can use a commercially prepared Koi fry food. Make sure to use only special Koi food with a high protein content and make sure to grind it into a fine powder before feeding it to your Koi fry.

After about 7 days you can start feeding a special Koi fry food consisting of fine powder pellets. When they reach 1/2 inch they can graduate to small pellets and as they grow you can gradually increase the pellet size until they are consuming the same food as their parents. Feeding is one of the most important components of raising Koi fry to be happy and healthy.

It is easy to overfeed your Koi fry and cause the water to become polluted. Young fry are very sensitive to ammonia. You must limit your feedings and provide a water change daily. The easiest way is to use water from your adult pond as long as your adult Koi are healthy and the quality of your pond water is good. You need to keep a watchful eye on water quality to prevent fungus.

If you observe these basic precepts you should have no trouble successfully raising Koi fry!

Alan Deacon
KoiCareBasics.com