What is the proper temperature for a kids spa?

The temperature should be around 20 to 25 degrees.

This is incorrect; at 20 - 25° F the water would be ice and at these temperatures C (68 - 77 F) the water would be way too cold to be considered a spa/hot tub. For children the water should be kept between 98°F to 102°F or 37°C to 39°C. A child should never spend more than 15 minutes in a spa/hot tub without exiting to cool off for at least 5 minutes. A child's body cannot regulate its internal temperature as well as an adult; these high temperatures can lead to several health issues that can become life threatening. NEVER leave a child in a spa/hot tub unattended.