i didnt say i will change the floss from the OLD filter every 2 weeks which is dirty already, regarding the new filter i will simply wash the sponge with aquarium water every month or so, but regarding the old filter which i will still run like u guys told me, FLOSS ONLY, no ammo chips or anything, i will change the floss in that old filter every mont or so too, that will be ok? and for example if i change the floss in the old filter i should wait ATLEAST 2 weeks and only then clean the new filter's sponge too so there are no problems, did i understand that correct? ok so like i said, do i need to get a new filter floss for my old filter now because its really dirty? or i think first i need to wait the first 2 weeks like i said because it has benefitial bacteria , 2 weeks starting tommorow that is because i will install the new filter tommorow, before i install the new filter i will take out the old filter, dump out all the chips and just leave the old dirty filter floss in it for 2 weeks and keep runing the old filter along with my new filer that i will install tommorow, should i change the filter floss in the old filter after these first 2 weeks?