To dry a filter or not to dry, that is the question

Ok so i want to buy a cartridge carbon filter like this one.

Whirlpool at Lowe's: Standard Whole House Opaque Pre-Filtration Housing

my question is, i am only going to use it for brewing, which i hope will be about twice a month. How should i store the filter when i am not using it? should i take the filter apart and take the carbon filter out to let it dry? or store it full of water?

Full of water means that stagnant water can grow nasties. dry means that the filter is exposed to air. Neither seems like that good an option.

Thanks in advance for your ideas

The problem with trying to dry an activated carbon filter is that you can't. It may appear dry externally, but internally it will retain moisture for a very long time. Regardless, IMO it's better to remove the filter from the housing, rinse it well with tap water and let it air dry as best you can. I really don't like leaving the cartridge sitting in the cannister full of water. The next time you use it, flush it well by running water through it for a few minutes first. This is about the best you can do. Only use the water in the pre-boil phase of brewing. The boil should kill anything that happens to get into the kettle. I've been using this method for years with the same cartridge without problems.

Definitely have your filter dry out! I put my cartridge next to my kitchen sink and after at least a week, when I am positive it is mostly dry I put it back in the assembly.