Before a single seed was planted, TÜV SÜD did the unglamorous part: it measured the water. Four samples, drawn on the same day into sterile containers — borewell water, tap water, the output of a conventional reverse osmosis purifier, and the output of a Crompton Rhion Biofier — and analysed immediately, to IS 3025 and APHA methods, with minerals by ICP-OES.
This is the table the germination study rests on, and it answers the question people actually ask: not is it safe, but what is left in it.
What the tap delivered
The tap water was hard and heavy. 1,462 mg/L of total dissolved solids, hardness of 636 mg/L as calcium carbonate, alkalinity of 561, and 6.3 mg/L of nitrate. Calcium at 165 mg/L and magnesium at 64. That is water nobody would want to drink untreated, and exactly the kind of feed both purifiers were built for.
What each purifier left
- Total dissolved solids: RO 105 mg/L. Biofier 152 mg/L.
- Calcium: RO 7.5 mg/L. Biofier 11.9 mg/L.
- Magnesium: RO 4.6 mg/L. Biofier 6.0 mg/L.
- Alkalinity (the bicarbonate that gives water its body): RO 52 mg/L. Biofier 125 mg/L.
- Hardness: RO 37 mg/L. Biofier 54 mg/L.
- pH: RO 7.32. Biofier 7.55.
- Nitrate: RO 2.2 mg/L. Biofier 0.24 mg/L.
Every one of those Biofier readings sits comfortably inside the Indian drinking-water standard, IS 10500. The difference is not that one water is safe and the other is not. Both are safe. The difference is what the safe water still carries.
The nitrate line is worth a second look
People assume that keeping more minerals means keeping more of everything. The nitrate reading says otherwise. Nitrate is a charged ion, precisely the kind of thing a CDI cell is built to pull onto its electrodes, and the Biofier water came out with less of it than the RO water did. Selective does not mean gentle. It means choosy.
Why a few milligrams matter
Eleven milligrams of calcium in a litre sounds like nothing until you remember that a seed, or a person, drinks two or three litres a day, every day, for years. The WHO’s own review of demineralised water makes the same point: drinking water is a small but constant contributor of calcium and magnesium, and water stripped of them contributes nothing at all.
The germination study that followed is what happens when you let seeds vote on that difference. The green gram test →
These figures are from one feed water on one day. Your own supply will give different absolute numbers; what the fifteen-condition IAPMO testing shows is that the pattern — more retained, still within the standard — holds across feed water from 250 to 1,500 mg/L TDS.
