Pond Water Testing

Why is pond water testing important?

Pond water directly influences the growth of your aquatic plants, the development of microorganisms, and the condition of your fish. To ensure your pond stays in top condition, it's crucial to regularly test the water parameters. This allows you to make timely adjustments and ensure an ideal living environment for your fish and aquatic plants. We recommend testing your pond's water parameters once a month.

Which water parameters should I test in my pond?

The water parameters in your pond are all interconnected through various processes. You'll find many articles on these different water parameters in our knowledge base. Below, we summarize the most important water parameters for your pond.

pH value pond

If the pH is too low or too high, or even fluctuates significantly, your fish will experience stress. This manifests as bloodshot gills and fins, and their mucous membranes can become damaged. Stress makes fish more susceptible to disease, as it significantly reduces their resistance and can ultimately be fatal. Moreover, the beneficial bacteria in your pond and filter will function less effectively at an unfavorable pH, creating a downward spiral where the pH deteriorates even faster. It is therefore essential to regularly monitor and adjust the pond's pH. The ideal pH for your pond is preferably between 7 and 8.5. If you have a koi pond or a pond exclusively containing other cyprinids, the pH is considered optimal between 8.0 and 8.5.
View our resources to change the pH value here .

GH value pond

The GH value indicates the dissolved minerals in your pond water, with important minerals like calcium and magnesium playing a role. Minerals are vital for your pond for two reasons:

• Minerals act as a carrier for CO2 in your pond.
• Minerals serve as nutritional salts for oxygenating plants.

For optimal plant growth, an ideal GH value is between 10 and 13. A lower value can lead to stagnant plant growth, while a higher value easily leads to limescale deposits on your oxygenating plants. Because rainwater contains no minerals, this results in a continuous decrease in the GH value of your pond.
View our resources to increase GH levels here .

KH value pond

Carbonate hardness indicates the amount of dissolved carbonate in your pond water. Carbonate is a chemical compound of calcium/magnesium and CO2, with this CO2 component being particularly important. Oxygen-producing plants depend on this CO2 for their growth. When the carbonate hardness is sufficiently high, it acts as a CO2 store in your pond. Essentially, sufficient CO2 is produced by bacteria in a healthy pond. However, for various reasons, the production by bacteria and the consumption by oxygen-producing plants can sometimes differ. Adequate carbonate hardness can compensate for these variations, which is known as the buffering effect. An ideal KH value for carbonate hardness is between a minimum of 7 and a maximum of 8.5.
View our resources to increase KH values ​​here .

Ammonia value pond

What we measure with test kits is the concentration of ammonia (NH3 and NH4+ combined) in the pond water. What we actually want to know is the amount of ammonia (NH3). Ammonia is harmful to carp at concentrations as low as 0.1 milligrams per liter. That equates to one part of ammonia in 10 million parts of water! Ammonia is released during the fish's digestion of food. It is therefore a waste product of digestion. Ammonia leaves the fish through the bloodstream and is released into the water through the gills. Contrary to popular belief, it is not the fish's feces and urine, but the ammonia released through the gills that is the biggest pollutant in the pond. The ideal ammonia level in a pond is 0.0 milligrams per liter.
View our resources to reduce ammonia levels here .

Nitrite value pond

Nitrite (NO2-) is produced in the biological filter as a result of ammonia conversion. This is part of the nitrification process. A nitrite level of 0.2 mg per liter or more is harmful to your fish. An excessive increase in nitrite levels in the pond can pose a risk of suffocation for the fish. Nitrite has the detrimental property of binding to the red blood cells in the fish's bloodstream. This hinders the normal function of these red blood cells, which are normally responsible for transporting oxygen from the gills to the fish's organs and muscles. The ideal nitrite level in the pond is 0.0 milligrams per liter.
View our resources to reduce nitrite levels here .

Nitrate value pond

The final product of the nitrification process is nitrate (NO3-). When the conversion of ammonia to nitrite by the nitrifying bacteria in the biological filter takes place, nitrate is ultimately formed. Compared to ammonia and nitrite, nitrate is considerably less harmful. While ammonia can be toxic from as low as 0.1 milligram per liter and nitrite becomes harmful above 0.2 milligrams per liter, nitrate only becomes a health problem for fish at concentrations well above 200 milligrams per liter. Although fish can tolerate quite high nitrate concentrations, we strive to keep nitrate levels below 50 mg/l. Many koi hobbyists maintain an upper limit of no more than 30 mg/l. Nitrate levels above 50 milligrams per liter create an additional risk of algae explosions, which we want to prevent because they are unsightly. Furthermore, these algae can cause slime on plants and fluctuate the pH level.
View our resources to reduce nitrate levels here .

Phosphate value pond

Phosphate enters our ponds through koi food. Just like nitrate, an excess of phosphate can lead to excessive algae growth. Besides being aesthetically undesirable, excessive algae blooms can suffocate our ponds and lead to sharp fluctuations in pH. This is particularly problematic for carp, as they are sensitive to it. Therefore, we strive to keep phosphate concentrations as low as possible.
View our resources to reduce phosphate levels here .