Reef Dosing Calculator: Alkalinity, Calcium & Magnesium
Estimate a supplement dose from your measured parameter, target and aquarium water volume.
US liquid gallons (1 US gal = 3.785411784 L). Switching units converts your entries.
Check the entered values and ranges before calculating.
Result
Understand a target correction dose
Test the parameter first, choose a target and enter the actual circulating water volume. The estimate scales the difference by the concentration stored for the selected preset. It does not measure your aquarium’s daily consumption.
Formula and units
Dose (mL) = (target − current) × (water volume in L ÷ 100) ÷ concentration. Concentration means the parameter increase per mL in 100 L.
Worked example
For a hypothetical liquid that raises calcium by 2 ppm per mL in 100 L, raising 50 US gallons (189.27 L) from 400 to 410 ppm would require about 9.46 mL in this model. This example does not specify a product or dosing schedule.
Assumptions and limits
Check the exact label and preparation against the preset before use. A powder requires a known solution concentration; an mL result is not a dry-powder mass. Observe product limits for changes and retest. A correction dose should not be copied into a daily dosing schedule.
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Frequently Asked Questions
Is this result my daily dosing amount?
No. This estimates the amount for the difference between your current and target values. A daily maintenance dose depends on measured consumption over time. Follow the product instructions for maximum corrections and retest before adding more.
Which aquarium volume should I enter?
Use the actual circulating water volume, including water in the sump and allowing for rock, sand and equipment displacement. You can enter US gallons or liters; the supplement result stays in mL.
Can I use the estimate with any product of the same brand?
No. Concentration, formulation and preparation matter. Verify the selected preset against your exact product label. The output is in mL of solution, not grams of dry powder; do not use it directly for a dry product. Follow label directions for separately adding supplements.
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