Ho72, A couple of years ago I spent and enjoyable hour speaking to a customer rep for Peak Battery Water who explained in detail the process used to manufacture their water products. Peak Battery Water is exactly that; a highly refined water product made primarly for the Battery Industry that uses the water in the manufacture of of industral & car batteries. The Rep said,in his opinion Peak is an excellent low-cost water product due to exact testing they perform for the manufacturing industry. He stated that Peak Water Products are manufactured for & sold under many brand names , including Prestone. Therefore , should you locate any brand of Battery Water it most likely will perform equally to Peak because most likely that's who manufactured the product.
Ho72, in the past a Chemist and a Industrial Water Quality Specialist have forwarded detailed information on water issues that were posted on past threads.
I have personally spoken at length to a Soda Industry Specialist/Consulant that oversees the preperation water products for human consuption. These folks are in demand because ,in fact, they are experts on matters regarding the scientific use of, or industral manufacturing of, or human consumption of water products.
Some information they passed along: The US Government does not normally test & certify distilled water products. Therefore,its difficult to know if what we are buying is a clean distilled water product or something of lessor quality an/of poor quality control. That is unless one directly contacts the producer for assurances regarding product purity. Lab/medical water products are required by Law to be exactly whats printed on the label;therefore, there are extra costs accociated with manufacture & testing that are is passed on to the end user.
In summary , Peak-type products actually meet or exceed quality assurance requirements that Industry requires for manufacturing needs. In theory, we (the end user) buy a high quality product at a relatively low-cost thats already been certified for purity for Hi-end users. We are insidential product users and to me that's a good thing. Everybody else spent the money to assure we get a great product cheaply. I also mention, the chemist wrote , we are only making steam for cleaning purposes. He believes that for our purposes using any certified distilled water would achieve a clean, pure steam. He opined (as most steam cleaning manuals note)that using ordinary tap water is ok; however,the minerals in tap water will clog the steamer innards , shorting the units lifespan. That is a fact.
Rinsing is another matter . From emails I have read many steamers swear by the use of nerl water or better for rinsing purposes.