Which type of mikveh is the ONLY valid option for purifying a male zav?
Halacha 8 (category six) states that only a natural spring with 'living water' enables a male zav to immerse and purify himself.
Question 2
Rainwater is flowing down a hillside in a torrent containing 40 se'ah. Can a person immerse in it?
Halacha 16 rules that even if cascading rainwater totals more than 40 se'ah, it is not acceptable for immersion while flowing — it must collect in a cavity or pool.
Question 3
Spring water flows into a stone receptacle and then flows out again. Can one immerse in the collected water in the receptacle?
Halacha 9 states that spring water that flows into a stone receptacle and then flows out becomes unacceptable for immersion — all the water in the receptacle is lost for this purpose.
Question 4
A wave breaks off from the sea and falls on a person. Does this purify him?
Halacha 17 states that when a wave separates from the sea and falls on a person or keilim, they are pure for ordinary purposes, provided the wave contains 40 se'ah — and no intent is required.
Question 5
Spring water that drips (rather than flows) — what is its purity category?
Halacha 13 teaches that water that drips from a spring, even if dripping continuously, has only the status of a mikveh — it does not impart purity as flowing spring water does, unless caused to flow.