[JanS]

Most of it depends on the load in your tank and the type of filter.

I usually do the back flush every 2 - 3 months and a tear-down every 6 months. I have never really noticed a slow in the water flow in the Eheims even after 6 months, so I just use the above schedule with good results.

 

[JanS]

I'm curious if the Eheim Pro II's flow indicator actually helps indicate whether or not it's time to clean your filter?

Good question.... I forget to even check mine since the hoses are turned toward the wall, and it's under a stand so it isn't easily visible. I'll have to remember to check it next time it's cleaning time.