Supplies for homemade carbon filter?

alright ive decided to make my own carbon filter. now i live close by a walmart super store and a home depot. i would like to know what supplies you guys use and if there available at those two stores?

https://www.rollitup.org/grow-room-design-setup/63004-my-3-carbon-filter.html
im using this i think it works good everyone else likes them alot cheaper than 100 dollars but not all wall marts have the stuff