We were recently given an alkalinity test kit from Tropic Marin for a product review, and we were very pleased with the kit’s quality and ease of use. To use the test kit, simply rinse the vial, fill it with 5 milliliters of aquarium water, and add the reagent drop by drop (shaking the solution between drops) until the color changes from green to a bright orange. It really is that simple. Each drop required for the titration equals one dKH (degrees of carbonate hardness). If you want greater resolution, double the water volume to 10 mL and each drop will then equal one half dKH.
To see the process of the test’s color change, continue reading below.
After the first couple of drops from the solution bottle, your test should be green (see image below).
After several more drops, you should see a color change from green to orange-red. This color change indicates the titration is complete. The number of drops required to change the solution from green to orange is equal to the degrees of carbonate hardness (dKH).
Again, the test kit was extremely easy to use and the results are comparable to what we’ve found with other test kits. The color change on the Tropic Marin test, unlike the color change of other test kits, is extremely dramatic. It takes all of the guess work out of the test, giving you a solid number instead of a “well it could be this, or it could be that” result. On top of all that, this test kit was about $3-4 cheaper than its competitors.