GH is the measure of the total mineral content (calcium and magnesium) of the water. Water hardness lies on a spectrum between ‘soft water’ or ‘hard water’ depending on the amount of dissolved minerals: the more minerals present, the greater the hardness. Hard water is responsible for the build-up of limescale. Minerals are essential for the health of plants and fish. This test kit measures GH in dGH (where one degree = 17.8 ppm as CaCO3).

The correct GH depends on the type of fish being kept.

• Soft water aquarium species, aim for a GH of around 3 to 6 °
• Hard water aquarium species, 10 to 15 dGH is the correct range.
• Most ponds, 8 to 12 dGH is ideal.

If your GH level is incorrect, test the GH of your tap water. The GH of tap water is determined by whether you live in a hard or soft water area. If the water is too hard for the fish being kept, alternative waters can be used, such as reverse osmosis or rainwater, to lower the GH. To increase the GH for aquarium fish, Ciano GH will raise the levels or calcium carbonate rocks (like ocean rock) can be used to provide a continual source of GH minerals. In ponds, use NT Labs Koi Care GH Minerals Up.

KH is the buffering capacity of water in your pond preventing sudden pH changes. KH, also known as “total alkalinity” or “carbonate hardness”, is a measure of the buffering capacity of the water in your aquarium. The buffering capacity refers to how well it can resist changes in pH. This test kit measures KH in dKH (where one dKH = 17.8 ppm as CaCO3). It is essential to maintain a minimum KH level of at least 4 dKH at all times. A KH of between 6 and 8 dKH is more desirable.

If your KH level is incorrect, check the KH level of your tap water. If the level is above 6 dKH, then regular water changes should keep the KH value in the aquarium topped up at a reasonable level. If the KH value of your tap water is below 6 dKH, you will need to add a KH buffer such as NT Labs Aquarium KH Up – pH Stabiliser or NT Labs Koi Care KH Buffer Up for ponds.

NT Labs Hardness Test Kit will help you understand the importance of water quality. By having the correct parameters and good water quality, it will help your fish and plants live longer, healthier lives.

Highly accurate, the NT Labs Hardness Test Kit contains liquid reagents which work by changing the colour of a water sample in relation to the concentration of a given substance. Simply count the number of drops it takes to alter the colour of the sample.

The tests are liquid drop tests from a calibrated dropper bottle, so all the drops are the same size. Just add your aquarium water to the test tube and count the drops needed. The back of the box details clear pictorial instructions so you can see what to do from the start. A set of colour coded stickers is provided to label both the test tubes and test tube lids, so you always conduct the same test in the same test tube avoiding contamination. Full instructions are included detailing optimum levels and suggestions for correction.

Suitable for tropical and coldwater aquariums. For brackish or marine set ups, we recommend you use NT Labs Marine Labs Test Kits to obtain the most accurate results.