When does a K&N panel filter require cleaning

[Alpine]

I have a K&N panel filter which looks like this:

http://img442.imageshack.us/img442/820/kn001smallcw0.jpg

As you can see, there is some dirt in the shape of a circle on the filter. Just wondering how dirty is dirty and when does a K&N panel filter require cleaning? Possibly the same as when a normal stock paper filter gets replaced? Or longer?

[Crapdaz]

should clean yours now, depends on the area you live in.

some can be between 10-20k

[souperman]

yeh. your filter looks pretty dirty.:(

i dont think there's a set schedule that you need to stick to. Just inspect whenever you service and if you see that it's dirty, or feel that the engine is not breathing as well as it normally does, then clean it.

there are cleaning instructions on the website for K&N
http://www.knfilters.com/cleaning.htm

[CB7_OWNER]

If u wanna keep the filter and your car's intake nice and clean, just clean the filter every oil change...for the price it cost of a kn recharger kit (approx $22 i think).. its well worth cleaning the filter than just when it looks dirty.

I clean my air filter every 5000k(change oil interval)