Filtering?
In order to keep the water in the spa clean and to strive for a good water quality, you should definitely filter the water. The more water is filtered, the better the water quality. During the filtering process, the water from the jacuzzi passes through the filter and the dirt sticks to the filter. Filtering alone is obviously not enough to ensure optimal water quality. In addition to filtering, you need to maintain the water level with Chlorine and pH. 

How often should you replace the filter?
This depends on various factors. Are there many trees near the spa? Do you go in the water a lot? Is there a jacuzzi party? 
But our golden tip: The more you change the filter, the better your water quality. 

Darlly filters bottom opening without thread
The Darlly spa filters are of very strong and good quality material. Because of this they have been the number one producer of cartridge filters in the world for a long time. These filters can be used in different brands and models of spas, jacuzzis, hot tubs, as there are hundreds of different types. 
The filters on this page have a handle at the top and an unthreaded opening at the bottom.