According to Halacha, what percentage of tzedakah given should go to a baal teshuvah? Did the Chofetz Chaim give a P’sak on this?

According to Halacha, do Mikvaot (which are outdoors, not covered by a roof) require hasgacha to be presumed kosher, or do the poskim allow for a Chazakah it remains valid even without supervision? Does it depend on the rain and weather cycle of the area? Sources please