Alkalinity Supplement Calculator

Enter your aquarium water volume, current and desired alkalinity level, and then select your additive of choice to find out how much you need to add to reach that desired alkalinity level.




This calculator is designed to provide a single adjustment dose to correct fallen alkalinity levels. Once your desired alkalinity level is reached, reference the manufacturer instructions for calculating your daily dosing amount.

Keep in mind your adjustment dose will be different from your tank’s required daily dose.

If making a large adjustment (more than 1.4 dKH) divide the dose up and add to the tank over the course of 1-2 days to avoid dramatic changes in water chemistry.

Powdered alkalinity additives should be thoroughly dissolved into solution before dosing. Dose liquid solutions slowly, into an area of high water flow avoiding direct contact with pumps, heaters and other equipment to prevent precipitation. Avoid allowing the solution to directly come in contact with living corals as well.

It is best to monitor pH during the initial dose and never allow changes of more than 0.20 pH per dose. Never dose calcium and alkalinity supplements back to back, give the tank 20-30 minutes minimum in between doses.

To maintain alkalinity levels once the target level has been reached, it is best to dose small amounts each day, sometimes even multiple times per day. This maintains that stability in your tank and prevents rapid changes in water chemistry that will stress out tank inhabitants if you were to dose large quantities at one time.

Test and monitor your alkalinity levels daily until your daily dosing regime is dialed and stable. Continue with weekly alkalinity testing to monitor the aquarium's progress. In aquariums with a significant population of growing stony corals, it is not uncommon to have to increase daily alkalinity doses every few months to maintain stable levels.

Download Bulk Reef Supply Saltwater Aquarium Water Parameters Chart

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