Rain water can be treated with simply the unactivated Sodium Chlorite solution (green bottle) as rain water tends to be acidic enough on its own. Depending on the initial water quality, you may use 1-5 drops per every 5 liters of rain water. Let it "do the job" for 24 hours before using it for drinking, cooking, etc
Taste may be used as a guide for adjusting the number of drops (if the treated water tastes too strong, you may want to reduce the drops or add more water per drops).
Purchase HealthWise Water Treatment Drops here:
1x pack - https://healthwise.best/healthwise-water-treatment-drops-single-bottle-130ml.html
5+1 free packs - buy 5 through the above link, and we will send you 6 bottles.