#4- another good money saver is poly fiber fluff and rolls. the rolls can be used to make filters or into pads for mechanical filtration in sumps & filters. the fluff can be used in canisters as a mechanical filtration the rolls go for about $8 for the smallest size and well.....you will have to check on the fluff for me :).
the poly pad can be washed over and over and save you lots of money. i used it im my filters so my filter cartridges dont get so filthy