The original Spa Pools (בריכות ספא) as we know them were made of wood and were very popular in Japan two to three hundred years ago. Then of course there were the Greeks, Phoenicians and last but not least the Romans, all of whom thought it was a cracking idea to have warm bathing coupled with massage. Moving quickly into more modern day times I have absolutely no doubt that back in time just over half a century ago when the Jacuzzi brothers Invented a portable whirlpool pump that they would not have had an inkling that this would go on to form such a large and developing industry.
Spa Pools and Jacuzzi style spas are now being made in most western countries to the highest standards and the development of the product continues at a pace. Apart from the original idea of being able to combine warm water and air to create the Spa effect there is no part of a Spa Pools (בריכות ספא) that has not had improvements and amendments made to technology and indeed the construction and manufacturing processes used in making a Hot Tub have gone through considerable changes.
Each and every Spa Pools manufacturer has tried to be at the cutting edge when introducing new ideas. The original Jacuzzi pump, when coupled with jets using an air-injection system, a mixture not unlike a kind of bubbly water-and-air was created. Originally Spa Pools used a simple idea that involved something like a vacuum cleaner motor but operating as a blower in some ways not unlike to blowing air into the hot tub in exactly the same way that we as children would have used a straw to blow bubbles in to a glass of pop.
Many modern Spa Pools (בריכות ספא) have the ability to bleed air into so that one is able to inject air into the Jets thereby increasing the pressure and movement of water to create a beneficial hydro massage effect.