Filter

My contribution to the Abstract Thursday challenge (thanks to Ingeborg for hosting) is a photo of a filter. Our hot tub has two big filters. I generally clean them every week. That means I rinse them with water (under high pressure) and then put them in a tube that can hold two filters and six litres of water. For the cleaning process I add some "filter clean", containing amongst others chloride. After a week I rinse them again and replace the pair in the tub with the cleaned ones.
The idea of the tube was passed to us by the man who installed the tub. Through using a limited space we also limit the amount of water and the amount of filter clean (better for the environment).