Chemicals for Hot Tub Start-Up

Filling your hot tub is one of the first steps of spa start-up. The next step is balancing the water for the first time. In this hot tub how-to video, learn how to test hot tub water, what chemicals to add to the hot tub, and the importance of adding chemicals in a specific order.

It's important before adding any chemicals to your hot tub that you carefully review the labels and review the size of your hot tub, specifically its fill volume, in your owners manual.

Hot tub chemistry start-up guide

First, we need to fill the tub. Be sure to check out our video about how to fill your hot tub. Along with our video, you can find information about the initial fill-up in your owners manual and at www.masterspas.com/customer-support.

Start by checking the chemical levels using a test strip. Most test strips allow you to check total chlorine, free chlorine, pH, alkalinity, and calcium hardness.

To balance these levels, you should have these chemicals nearby: a pH increaser, a pH decreaser, and sodium-dichlor chlorine granules.

When retrieving a test strip, make sure that you are not contaminating the remaining strips in the container. Follow the instructions on the packaging for dipping and discerning the results.

Start by balancing the alkalinity pH, as needed. The pH should be between 7.4 and 7.6 and alkalinity between 100-120 parts per million.

Next, we'll need to sanitize the water and the components of your hot tub. MasterSpas recommends using dichlor granules for sanitation. It works best with the EcoPur and the ozone water care systems.

For initial startup, the free chlorine levels to be higher than what is best for daily use to ensure proper startup sanitation of the water and components. You should aim for a level around 5 to 8 parts per million. Wait an additional 30 to 60 minutes before re-checking the free-chlorine level, and do not allow anyone to get in the hot tub until the chlorine levels have dropped between 2 and 4 parts per million, which is a recommended range by the way. One last test and that's it.

Once the chlorine levels dip into the recommended levels, your water is balanced and ready to enjoy.

For European countries, please refer to this Water Chemistry Guide for appropriate chemical levels per BS EN 17125:2018.