When water is exposed to an external magnetic field (typically by flowing through or past a permanent magnet), its molecular structure changes in measurable ways without altering the chemical composition of the molecules themselves. The magnetic interaction promotes the formation of clustering structures — ordered arrangements of water molecules linked by linear and ring hydrogen bonds — alongside increased polarization and altered electronic transition dipole moments.
Key physical changes documented (Pang & Deng 2008):
Saturation effect: There is a maximum beyond which additional exposure time or field strength produces no further change.
Memory effect: These structural changes persist after the field is removed. Duration depends on field strength applied:
| Field Strength | Memory Duration |
|---|---|
| 600 G | ~35 min |
| 2000 G | ~45 min |
| 3000 G | ~58 min |
| 4000 G | ~60 min |
Memory degrades faster at higher temperatures — MW loses effect rapidly above ~35°C.
Agricultural significance: Reduced surface tension means magnetized water penetrates soil pores and seed coat more efficiently. At the cell membrane, the altered water structure increases permeability to calcium ions, which triggers the calcium-signaling cascade and downstream metabolic activation (see [[mechanism-calcium-signaling-cascade]]). This two-stage mechanism — physical water restructuring followed by membrane-level calcium signaling — explains both the germination improvements and the broader growth stimulation documented across species.
Dosing matters: Goldsworthy et al. (1999) showed that weak conditioning (100 kHz for 5–30 s) stimulated yeast cell growth by 53% via Ca²⁺ permeability, while strong conditioning (2 min) inhibited growth by 50% through membrane damage. The optimal window is species-specific and requires calibration.