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Monitor the total hardness of your aquarium or pond water accurately with Sera GH Test 15ml — an easy-to-use water test designed to measure the concentration of dissolved calcium and magnesium minerals.
General hardness, also known as GH, is an important water parameter that influences fish health, biological processes, and successful breeding. Different fish species require different hardness levels, so regular testing helps you create water conditions that closely match their natural habitat.
The test uses a simple drop-count method. Add the reagent drop by drop until the sample changes from red through brown to green. The number of drops used directly indicates the total hardness in °dGH. For example, five drops represent a result of 5°dGH.
One 15ml bottle provides testing capacity for approximately 420°dGH, making it a practical option for regular aquarium and pond water monitoring.
• Brand: Sera
• Product Name: GH Test
• Product Type: Aquarium and Pond Water Hardness Test
• Volume: 15ml
• Measures total or general hardness (GH)
• Suitable for freshwater aquariums and pond water
• Testing capacity of approximately 420°dGH
• Simple drop-count testing method
• Each drop represents 1°dGH
• Clear color change from red through brown to green
• Helps select suitable fish according to water hardness
• Supports healthy fish keeping and successful breeding
• Ideal for routine water-quality monitoring
Shake the reagent bottle well before use.
Rinse the measurement vial several times with the water being tested.
Fill the vial to the 5ml mark and dry the outside.
Add the reagent one drop at a time, gently shaking the vial after every drop.
Continue until the color changes from red through brown to green.
Count the drops used. Each drop equals 1°dGH.
Clean the vial thoroughly with tap water after testing.
• For GH levels that are too low, use Sera Mineral Salt.
• High total hardness can be reduced by mixing the water with reverse-osmosis water.
• For softer water, use Sera Blackwater Aquatan or filter through Sera Super Peat.
• Freshwater aquariums
• Garden ponds
• Tropical fish aquariums
• Community aquariums
• Breeding aquariums
• Routine general-hardness monitoring
Do not return tested water to the aquarium or pond. Close the reagent bottle immediately after use and store it at room temperature, protected from light and out of the reach of children.
Order processing and verification typically takes 2-3 business days depending on demand levels and product shortages.
The expected time of arrival is 8-15 business days.
You will always receive an email once your order is processed as well as a tracking number.
We have a 30-day return policy, which means you have 30 days after receiving your item to request a return.
