As always, thanks 'orama.
Since you have 2 filters you can rinse & squeeze the cartridge under running tap water...but not a good idea to clean both filters the same week. The floss type doesn't last nearly as long as foam & it kind of stretches out of shape. The carbon adds to the stretchiness, it settles down to the bottom even if you're careful.
Indeed, I was considering rinsing these out in tap water for the very reason you stated -- that I'm running two filters (and because the Aqueon has those "bio holsters" the cartridges sit in, which are supposed to be where the BB resides in these units anyway). I've also read that people have gotten good results by just blasting these carts with a hose or kitchen sink hose, which usually loosens up debris caught in the carbon. I have to say. I don't usually see ANY dirt or debris come off these carts when I "swoosh" them around in removed tank water; the pads are kinda dark and dirty-looking, but perhaps this is all BB all over them?
To be honest with you, the AquaClear foam block in my 110 seems to "deform" and get "out of shape" a lot more than the floss around my Aqueon carts do -- the center of the block, right now, is bowed pretty badly in the center, and it's not that old. Two Tank Administration told me in a different thread that this is common now with the material Fluval uses to make these...
I would gradually quit using the carbon & save the packets for when you might need them (I have many! carbon pkgs). I take the floss sleeve off it's frame, rinse & slide it back on. It's good for 10? rinsings or so, less with carbon &/or aggressive squeezing & rubbing. It doesn't have to get perfectly white but try to get the dark spots out.
Thanks; actually, I have done more than 10 rinsings already, I'd say, with these two carts, and the floss isn't falling apart -- however, as I hinted at above, the stains don't seem to be coming off them, but I don't know if this stuff is crud and debris attached to the floss or BB.
As for the carbon, I'm really not concerned with it; I only use the stock Aqueon carts because they're designed for the filter and it's convenient. But I haven't bought new carts since setting up the tank, instead swooshing and reusing the ones that are in there now -- in place since the tank cycled (you remember the thread of mine about THAT). This all plays in to why I began this thread in the first place -- I wanted to know if reusing these floss-covered cartridges was okay in the same way most of us reuse and clean the foam blocks of AquaClears.
I believe the carbon "leeching" toxins back into the water is a myth. It just quits adsorbing & becomes just another place for beneficial bacteria to grow. It really only works a short time, like maybe a week or so at most. I use carbon mostly to remove meds along with water changes. I change the carbon every few days when doing that.
Thanks for confirming that; yeah, as I said, I don't NEED the carbon -- I only leave it in the carts because it's there already.