The recommendations are to always use distilled or reverse osmosis rather than tap water. If the tap water is coming through old pipes, it could pick up metals that increase the chance of DOS (dreaded orange spots) in the soap. There can also be issues with other “impurities”. Surprisingly (to me at least), sea water has some of those same impurities, such as magnesium and calcium, but it does not seem to cause problems in soap. Some here use rainwater for soap, but if you do that, I think you should wait to collect it until after the rain has had a chance to clear impurities out of the air. Collect it fresh from the sky in a pail, for example, rather than off a roof. You may also want to filter it if there are obvious particulates.Can you use regular tap water for the feux sea water or does it need to be filtered mineral water or distilled water for definite ? Distiiled water is expensive so making a quart ( About 946ml )is a lot .
Also can the recipe be used HP and also work with the addition of shae butter ?
Thanks