This item is in stock in our East and West Coast warehouses
Tests tap water and freshwater aquariums for general hardness (GH) and carbonate hardness (KH). Helps detect stress on fish caused by rapid pH shifts, which result from low KH levels and helps aquarists duplicate the natural habitat of their fish.
KH & GH Test Instructions:
What is Carbonate Hardness (KH)?
Carbonate hardness (also known as alkalinity) is the measure of carbonate (CO32-) and bicarbonate (HCO3-) ion concentrations dissolved in water. These minerals are present in municipal, well, and bottled spring water. The level of carbonate hardness in tap and bottled water depends on the source of the water and the treatment processes it has undergone. Carbonate hardness helps stabilize pH in the aquarium. An aquarium with a low KH level (50 ppm or less) will tend to be acidic. Aquariums with very low KH are subject to rapid pH shifts, if not monitored carefully. Water with a high KH level (= 200 ppm) usually has a high pH. The Aquarium Pharmaceuticals KH (Carbonate Hardness) Test measures KH in German degrees (°dKH). To convert °dKH to parts per million (ppm), multiply °dKH x 17.9.
Directions for Testing Carbonate Hardness (KH):
General hardness is the measure of calcium (Ca2+) and magnesium (Mg2+) ion concentrations dissolved in water. These minerals are present in municipal, well, and bottled spring water. The level of general hardness in tap and bottled water depends on the source of the water and the treatment processes it has undergone. Hard water (= 200 ppm) is high in calcium and magnesium, while soft water (50 to 100 ppm) is low in these minerals. The Aquarium Pharmaceuticals GH (General Hardness) Test measures GH in German degrees (°dGH). To convert °dGH to parts per million (ppm), multiply °dGH x 17.9.
Directions for Testing General Hardness (GH):
Aquarists seek to provide a healthy aquarium environment by duplicating the water conditions of the natural habitats of their fish. Tap water rarely provides the water conditions necessary to maintain an optimal aquarium. Some tap water supplies have a very low KH level (below 3 °dKH). This type of water has very little pH buffering capacity and can contribute to wide pH swings in the aquarium. When water evaporates from the aquarium, it leaves behind hardness ions. Topping off with tap water simply adds more minerals to the aquarium, resulting in a steady increase in GH. It is therefore necessary to test the GH and KH frequently to monitor water quality and prevent stressful conditions from occurring. Use the table below to create the ideal water hardness levels for your aquarium fish. When keeping a community aquarium with a variety of tropical fish, adjust the GH and KH to 3° - 6° (50 - 100 ppm).
GH & KH RANGE - Aquarium Life
0°-3° (0-50 ppm) discus, arowanas, elephantnose, neons, cardinals, live plants
3°-6° (50-100 ppm) Most tropical fish including angelfish, cichlids, tetras, botia, live plants
6°-11° (100-200 ppm) Most tropical fish including swordtails, guppies, mollies, goldfish
11°-22° (200-400 ppm) Rift lake cichlids, goldfish, brackish water fish
Reducing General Hardness
General Hardness can be lowered with Aquarium Pharmaceuticals Water Softener Pillow. The ion exchange resin in the Water Softener Pillow lowers GH by removing calcium and magnesium ions. The Water Softener Pillow will not lower KH. Partial water changes with deionized water will gradually reduce GH to the desired level.
Increasing General Hardness
African cichlids and brackish water fish require hard water with a pH of 8.2. Commercially available African cichlid or marine salts will increase GH and KH levels.
Lowering Carbonate Hardness
ALowering KH is best accomplished by diluting the aquarium water with deionized water. Deionized water contains no KH or GH. Partial water changes will gradually reduce KH to the desirable level.
Increasing Carbonate Hardness
KH can be increased with Aquarium Pharmaceuticals PROPER pH™ buffers. PROPER pH 6.5, 7.0 and 7.5 are non-carbonate buffers that automatically adjust pH and increase KH. PROPER pH will raise or lower pH, stabilizing it at the pre-set pH level. PROPER pH 8.2 is a carbonate buffer suitable for marine and African cichlid aquariums.
Aquarium Pharmaceuticals Aquarium Supplies
Aquarium Pharmaceuticals (API) has been helping people take good care of ornamental fish for over 40 years. Their research and development scientists have advanced the care of fish with all-natural medications, stable bacteria for biological filtration, one-bottle test kits, consumer-friendly dosing caps and much more. They’ve received over 25 global patents for their breakthrough innovations in the aquatics industry. And they continue to look for ways to improve the fishkeeping experience for hobbyists. Research. Experience. Dedication to scientific, quality treatment for healthy fish. It’s what makes API the first choice of aquarium owners. API manufactures and sells hundreds of products across many different product categories, including aquarium and pond treatments, aquarium equipment, aquariums and fish nutrition.
Accessories for API Freshwater GH & KH Test Kit