I've been searching for some cost effective ways to circumvent buying Marineland products outright. I have read that the rite size cartridges with the carbon built in isn't totally necessary for outstanding filtration, and generic pads and be used (cut to size, of course) and the media containers can be filled with polishers/filter floss. What do you all think?

yes, most people in the community believe carbon media is not necessary unless
you are removing med in your tank... and yes,... those generic pads or sponges or
synthetic fiber works perfectly in lieu of it....

You normally find that you will pay more if you buy the media that is made by the filter company themselves. However, if you purchase some nonbranded media and chop it to the size needed then you can sometimes save a lot of money. I agree with Paul, forget carbon altogether

I use poly-floss in ALL my filters as mechanical medium. I also have some carbon on-hand should it be needed. I have found that fiber-floss surpasses any other material for medium. Because you don't pack it tightly, it creates more particle trapping surface area.

I run 8-10 filters plus a wet/dry. Try to remember all the different filter sizes is nuts. Now I buy a single bag of poly-fil at WallyWorld for $3.00 and it lasts several months."Poly-fil" brand doesn't pack down as much as some of the others ("Buffalo Snow")yet surpasses any other medium.