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Aquarium TDS Calculator

Calculate the water change volume needed to bring Total Dissolved Solids (TDS) down to a target level using RO water.

gal
ppm
ppm

RO Water to Swap

27.50 gal

Water Change %

50.0%

TDS Reduction Goal

200 ppm

Note

Assumes RO/DI water at 0 ppm TDS.