Water Testing – Carbonate Hardness

Carbonate Hardness, KH, is the measure of the amount of Calcium and Magnesium found in your pond. These two elements play an important part in the health of fish. Calcium and Magnesium help to neutralise acids and stabilise pH levels. When people talk about HARD or SOFT water, this just indicates that your pond is  high or low  in these minerals. These minerals can play a role in how well treatments, such as algaecides or medicines, work. The KH will also play a part in how well the good bacteria in your pond works as the bacteria needs the minerals to survive. The effects of the SOFT water might not be seen at first but it will gradually take effect. With the good bacteria dying the ammonia and nitrite levels will begin to spike and without the needed calcium and magnesium in the water there is no buffer to prevent harmful pH swings. This will lead to the ill health of fish and even death. 

Testing your KH regularly should be done if you use rainwater in your pond. The mineral levels in rainwater can vary greatly. Rainwater is naturally SOFT but when it falls to the ground and makes it way into waterways or flows over rocks the water will pick up minerals such as Calcium and Magnesium which begin to make it HARD but this may not always be the case. To raise the level of Hardness in your pond we recommend using Hardness Plus. Use 30g (25ml) per 1,000 litres of pond water to increase carbonate hardness by one degree. Adjust by one degree at a time over a few days, test regularly to reach an ideal of seven to ten degrees carbonate hardness. Testing of the pond water can be done using the Carbonate Hardness Test Kit.

You can drop in to The Pond Shop with a water sample and we can perform a Water Test for just $5.00. If you have any concerns or would like to speak to someone about a particular problem you are having with your pond you can send us an e-mail, give us a call or come and speak with us in the shop.