In Jain practice, boiled-and-filtered water (ukāḷū/ukālo) is used fresh and not stored long.

• Best guideline for householders: Use within 24 hours of boiling when kept in a clean, covered steel or glass vessel at room temperature.
• In hot/humid weather: Prefer to finish within 12 hours.
• If you refrigerated it: Still try to finish within 24 hours; traditional practice avoids keeping it longer. If it has been stored longer, re‑boil once and then finish the same day.
• Do not “top up” the vessel; empty, wash, dry, and then refill with freshly boiled water.
• Pour without dipping cups or hands; keep the lid on; discard if there is any off smell, taste, cloudiness, or if the vessel was touched inside.

Tradition notes

• Shvetāmbara ascetics and lay vows during Chaturmās commonly follow the 24‑hour limit from boil time.
• Digambara ascetic discipline is stricter; householders still generally follow the 24‑hour guideline.

This preserves ahiṁsā by minimizing re‑growth of living microorganisms while keeping the practice simple at home.