I just wanted to chime in, I purchased a new blue "frost proof" hose from Ebay. "drinking water safe" but the foul taste was truly awful. This hose is 100 feet long, most of its run is in full sun, It is VEVOR brand. Our RV is currently stationary, used as a
"mother-in-law" cottage at my daughters house. The hose does not get a lot of flow.
I filled the hose with baking soda water, & let it sit for an hour or so. after flushing, the water tasted fine, but that might be a result of the flushing. the water in the hose may very well re-saturate with whatever as it sits in the hose, especially with the heat" on.
Unfortunately, the (aluminum?) hose fittings have begun to corrode, with white bits collecting in the screens. Well I had planned to install a filter set any way.
( I have other "garden" hoses with silver (aluminum?) fittings that do not appear to corrode, but they seem to have a brass or copper colored lining in the fittings)
Bottom line ... While I have a VEVOR sewage pump, and a VEVOR pressure washer pump that work ok so far, I do not recommend the VEVOR heated water hose.
The E-bay seller gave me a partial refund ( since I was too lazy to box it up & send it back), but I no longer have the opportunity to post a review on E-bay.
Happy thoughts, CE