Hi,

I am referring to filters which do no get blocked.

It all depends on the size and type of the filter, the stocking levels, water temperature and feeding rates.

If you have chamber filters with low stocking levels, you hardly have to clean during winter.

If you have Ultrazap filters, you might have to clean every second day in summer depending on the amount of organic matter in the pond.

I clean my sandfilters (backwash) in summer every fourth day and flush my chambers once a week and clean them thoroughly once a year(before summer)
In winter, I clean my sand filters once a month.

When you see your flowrate decrease substantially, you should clean. That can be every second day or once a week or even once a month.

Hi,

I clean my Ultra Zap Bio Filters once a year in August, the sand filters are back-washed every second day and once a month I open and “turn” the filter.

It really depends on what type of filter you have.

I clean my mechancal vortexes between once or twice a week.

My sand filter that i use as a polisher every second week.

My ultra zap pressure filter i clean once a year.

I never clean my biological vortexes with Kaldness K1 in it. I mearly give them a quick 5 second flush once a month or so.