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Testing your aquarium’s water parameters regularly is an important part of keeping and maintaining a healthy environment for your fish and invertebrates. Fritz General Hardness (GH) Test kit is a liquid-reagent-based test that accurately measures GH in freshwater aquariums. The kit contains the required reagents, a test tube and instruction card with test color chart.
General hardness (GH) measures the concentration of dissolved minerals (calcium and magnesium) in the water. Often overlooked, GH plays a critical role in aquarium health. These minerals support key physiological functions in fish, invertebrates, and plants, including skeletal development, osmoregulation, and enzyme activity.
Testing and maintaining appropriate GH is important for the long-term health of your aquarium’s inhabitants. Calcium and magnesium deficiencies can cause poor growth in fish, molting difficulties in freshwater shrimp, and stunted growth and development in plants — leaving imbalances unaddressed can ultimately lead to stress and disease.
To remove childproof safety cap, push down while turning.
Fill a clean test tube with 5 ml of water to be tested (to the line on the tube).
Holding the GH test solution dropper bottle upside down in a completely vertical position, add one drop at a time. Cap the test tube and gently shake between drops. Count the drops as they are added.
The test is complete when the water in the test tube turns from yellow/orange to green (after having been gently shaken).
Start
End
If you have difficulty discerning the color of the test solution is added, remove the cap from the test tube and while holding it over a white background and look down through the tube.
See conversion chart. The number of drops needed to turn the water from yellow to green determines the GH value.
Number of drops | GH value (ppm) |
|---|---|
1 | 17.9 |
2 | 35.8 |
3 | 53.7 |
4 | 71.6 |
5 | 89.5 |
6 | 107.4 |
7 | 125.3 |
8 | 143.2 |
9 | 161.1 |
10 | 179.0 |
11 | 196.9 |
12 | 214.8 |
DO NOT allow test solutions to get into aquarium. Read and follow all precautions on the product label.
Soft water fish, like Discus and other South American cichlids: below 4 dGH ( 0 – 70 ppm)
Tropical community fish, like tetras and betta: 4-8 dGH (70 – 140 ppm)
African Rift Lake cichlids: above 8 dKH (140+ ppm)
To decrease the GH of your water, perform partial water changes with water with a lower GH (such as RO/DI.)
| Item # | Case QTY | UPC |
|---|---|---|
| 75004007 | 12 | 080531040072 |
