I like to filter before I bulk age so that I dont have t do any more rackings as what comes out after filtration will be sediment free. i would add k-meta to bottom of empty carboy and filter right on top of it. It should be clear before you filter your wine or you will just clog up your filter and have lots of problems and most likely have to change filters in the middle of the process. I typically clear my wine at least 2 weeks with a fining agent and then rack off that for a month and then filter into clean carboy with k-meta in first, this way you are mixing up the kmeta with the wine pouring in and also dont get a volcano when you do stir a little to make sure the k-meta is thoroughly mixed in. It is absolutely worth aging for that period of time.