Calculate the exact amount of water-soluble fertilizer needed to achieve target nutrient concentrations (PPM) for hydroponic systems, greenhouse crops, and indoor gardening.
Fertilizer Required
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Nitrogen (N) PPM
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Phosphorus (P) PPM
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Potassium (K) PPM
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Total Dissolved Solids
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Mixing your own fertilizer solution saves money, allows precise nutrient control, and provides fresher nutrients than pre-mixed solutions. It's especially beneficial for greenhouse growers and hydroponic systems.
Use distilled water or reverse osmosis water for best results. Tap water can work but may contain dissolved minerals that affect nutrient ratios and total dissolved solids measurements.
PPM calculations are quite accurate for major nutrients (N-P-K). However, total dissolved solids will be higher due to minor elements, trace nutrients, and carrier compounds in the fertilizer.
Nitrogen PPM measures only the nitrogen content, while TDS (Total Dissolved Solids) includes all dissolved materials including other nutrients, salts, and carrier compounds. TDS is typically 3-5 times higher than nitrogen PPM.
While possible, gram measurements are more accurate. If using tablespoons, note that 1 tablespoon of typical fertilizer weighs approximately 12-15 grams, but this varies by fertilizer density.
Most plants tolerate 200-400 PPM nitrogen. Seedlings need 100-150 PPM, mature plants can handle 300-500 PPM. Always start lower and increase gradually to avoid nutrient burn.
Fertilizer labels show P₂O₅ and K₂O, not pure P and K. To convert: P = P₂O₅ × 0.436, K = K₂O × 0.83. Our calculator handles this conversion automatically.
Yes, warmer water dissolves fertilizers better. Cold water may not fully dissolve concentrated solutions, leading to precipitation. Use room temperature or slightly warm water for best results.