How Do Hot Tub Jets Work?


Yes, even if it is hard to believe, there is a science behind hot tub jets. Ultimately, each jet is powered by the water pumps and flowing water. Water is taken in through the filter or suctions, and is then pumped through the heater and back out. 

This flow is what keeps a hot tub filtered and hot. Jets also have air put into the line, increasing their power and cooling effects. Additionally, a small hole for air intake is opened or closed using an air controller. This adds or removes air from hot tub jets. 

Alongside this, diverters offer great control to the hot tub user. A diverter is a valve that redirects water straight from your hot tub to other directions. Simply put, this circulates water coming from the jets. 

Hot Tub UK / Google Stock Images

Hot tubs use a pump and heater to heat the water and circulate it throughout the hot tub. The flow of water through the pump, heater, and pipes keeps the water filtered and hot. 

Your hot tub can have three different types of jets, and they all work in the same way as explained above. The three types of jets are:

  • Moving jets: These jets push air and water through plumbing lines, and can provide users with the best low-impact massages. These types of jets are generally the ones that cause bubbles or water movements, because water is being pumped with a bit of force. 
  • Rotary jets: This type of jet uses the power of water and air, providing a consistent stream of water into your hot tub. There isn’t too much of a pressure change in these types of jets, and water may even be stationary at the surface; however, steady streams of water circulate the tub. 
  • Directional jets: Known as the most common type of jets, these jets allow users to move them to different positions so that there is a constant flow of water wherever it is needed. 

Generally, hot tubs need anywhere from 20-100 jets. It really is up to you and the kind of brand you purchase. The number of jets per hot tub will be based solely upon the few factors listed below: 

  • The pump to jet ratio
  • Power requirements and the cost of running
  • Risk of leaks 
  • Lack of variation 
Pool Spa Forum / Google Stock Images

Do hot tub jets shoot water or air?

Even though a few types of jets can be found in your hot tub, they typically don’t just shoot water or air out. However, if we look at the two most common tubs, air tubs and whirlpools, there are differences in how their jets work. 

A whirlpool does shoot jets of water; however, it’s not as intense as it sounds. Jets shooting out water in this type of tub is due to the water pump system. On the other hand, air tubs will release more air in their jets, instead of water, but use the same pumping system.  

The Hot Tub and Swim Spa Company / Google Stock Images

What controls jets in a hot tub?

A small hole that is used for air intake opens or closes, which controls the jets in a hot tub. This small hole is called a venturi. Each venturi will add or remove air from the hot tub, and create a nice circulating bath.


  • Jason

    Jason is an experienced writer, having contributed to many popular websites over the years. He currently writes for Big Hot Tub, a blog about everything hot tubs. When he's not writing or working on his blog, Jason enjoys spending time with his wife and two young children.