Refilling 4 inch Ventech Carbon Filter

Hopefully someone here can help with this. I have a few 4 inch ventech fan and filter combos I bought through amazon and I understand they can be refilled but have no idea how to do it. Any help will be appreciated. Here's a link for the to filter I have.

http://www.amazon.com/gp/aw/d/B005KMETHS?pc_redir=1405440656&robot_redir=1

Just buy a new filter, dont bother refilling it as it will cost about the same for the carbon. Carbon is expensive!

hey can only be refilled if they have a cap as on of the 3 legs
....................i am not sure if your brand if refillable but i know of these ppl
http://www.ebay.com/usr/foothill-carbon-filters?_trksid=p2060778.m1438.l2754

they are from USA ......they sell refillable carbon scubbers .....any size u need....heck they have Air polishers too

i own the 4 inch x12 and the 6inch x 18 ...............the best part is they sell u the carbon to refill it when u need it...........and it is cheap compared to getting a whole new filter (atleast from them it is)

Turns out they are refillable but I need to buy a riveter and rivet removal tool. If I can source carbon cheap enough it could be worthwhile. I don't want to have a bunch of filters to get rid of.

I wanna say its gonna come from a pet supply store..... but research that... It will be important to get the correct type and size of carbon pellets for optimum airflow/surface area for odor scrubbing...

(Sorry, I used to really know all this, but that was like 3 yrs and a LOT of weed ago and its real hazy now)

Thanks for the info. I really appreciate it. I'll be sure to check out other brands of filters and post any info on what I end up doing. I ended up purchasing and Ipower 4 inch reversible carbon filter which you can flip to get more use. I needed a third fan and filter anyway.