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Fertilizer Dosing Calculator
Work out how many grams of dry salts (KNO₃, KH₂PO₄, K₂SO₄) to add each week to hit your target N-P-K levels in parts per million.
Target ppm is the weekly rise, not the absolute level — your water change resets the tank each week. Defaults are classic low-tech (10/1/10) and EI-style (20/2/20) values.
Dry Salts per Week
KNO₃
1.63 g
nitrate source
KH₂PO₄
0.14 g
phosphate source
K₂SO₄
2.23 g
potassium source
Per Dose
1.33 g
split over 3 doses
Weigh dry salts to ±0.1 g. Split the weekly total evenly across your doses. For traces, a pinch of a commercial trace mix after each water change is enough for most tanks.
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