How this calculator works
Because phosphate targets are often very small, the calculator prepares a stock solution first. Enter the PO4 increase rather than the final concentration and verify the result with a suitable test.
Common questions
Why is the default increase only 0.01 ppm?
Phosphate is commonly adjusted in small steps. A dilute stock solution makes those doses easier to measure accurately.
Can I dose the dry salt directly?
A stock solution is usually easier to measure and distribute evenly, especially for small aquariums and small corrections.