Peterson pipe filters.......

Depends what you are smoking.
After my pipe has cooled down I always remove my 9mm filter and see what shape it is in. If it looks okay I'll let it dry and put a fresh one in the pipe for the next smoke. I probably get 2-4 bowls per filter with this kind of rotation and have never had a problem. I bought a box of a couple of hundred when I last ordered a pipe from Europe which makes them pretty cheap.
I do not smoke aromatics or any particularly wet tobaccos which might change things.

Just make it simpler for yourself and don't use a filter and one less thing to be concerned about. :wink:

Take charcoal filter, throw in trash, use a pipe cleaner instead. I never liked the charcoal filter but ever since getting this tip from a forum member I love it.
http://postimg.cc/image/49n0mctgl/

One filter per smoke, or use an adapter. Smoking without is not an option for me, the draw is way too open, and you have a huge area that collects crap and needs to be throughly cleaned more often.

I do like Castleford and Big Ben filters. Usually only get two smokes out of each filter, and that is indoors. Outdoors in South Louisiana I have to replace one every time. I have tried Vauen and Stanwell filters, and do not like them as much. They have a tighter draw than the Castleford and Big Ben do. I have also tried the Savinelli Balsa for 9mm, and while they seem to not hinder the draw, they don't absorb the moisture as well.

I have several pipes that can use filters, but I hate the idea of using them. I try, if at all possible, not to take my pipe apart until I wish to do a good cleaning. With a a filter that is obviously impossible as they must be changed after a few smokes. I like the ability of at least having the option of being able to run a pipe cleaner through the stem while smoking if needed, albeit I rarely do so. But, with any type of filter you obviously cannot do so. Also, through the years, I've gotten in the habit of running a pipe cleaner through the stem into the bowl (if possible) when I load a pipe, which again, is impossible with any type of filter in the way. Then there is that crazy little pesky quirk when a small piece of tobacco gets stuck in the shank which can easily be taken care of by running a pipe cleaner through the stem, but if there is any type of filter in the way... ? Just my personal opinion on the folly of filters. :wink:

I have a number of pipes that call for filters. I've installed non-filter adapters in all of them. Without the adapters the draw isn't right and they collect all sorts of stuff in the place where the filter is supposed to go. I like they way they smoke without the filters but that's a matter of personal taste.

The filter adapter is a simple tube that you put in the filter space and it typically reduces the airway from 9mm to 3-4mm. Here's one: