API GH & KH General & Carbonate Hardness Freshwater Aquarium Test Kit

For Testing KH

1. Rinse a clean test tube with water to be tested.

2. Fill the test tube with 5 ml of water to be tested (to the line on the tube).

3. Holding the bottle vertically, add KH Test Solution, one drop at a time. Be sure to count the number of drops being added.

4. Cap the test tube and invert several times after each drop.

5. The test is completed when the water in the test tube, after having been shaken, turns from blue to yellow. If you have difficulty discerning the color after the first drop of test solution is added, remove the cap from the test tube and, while holding it over a white background, look down through the tube.

6. The KH value is determined by the number of drops of test solution that must be added to turn the water in the test tube bright yellow.

For Testing GH

1. Rinse a clean test tube with water to be tested.

2. Fill the test tube with 5 ml of water to be tested (to the line on the tube).

3. Holding the bottle vertically, add GH Test Solution, one drop at a time. Be sure to count the number of drops being added.

4. Cap the test tube and invert several times after each drop.

5. The test is completed when the water in the test tube, after having been shaken, turns from orange to green. If you have difficulty discerning the color after the first drop of test solution is added, remove the cap from the test tube and, while holding it over a white background, look down through the tube.

6. The GH value is determined by the number of drops of reagent that must be added to turn the water in the test tube green.

Carbonate hardness, also known as alkalinity, is the measure of carbonate and bicarbonate concentrations dissolved in water. These minerals are present in municipal, well, and bottled 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 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 usually has a high pH.

General hardness is the measure of calcium and magnesium 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 is high in calcium and magnesium, while soft water is low in these minerals.