spwen i think what you saw were cleaning sponges.
I use the AquaClear Filter sponge and it works good, also keeps small fish out of the filter. But if you do have moss floating around in the tank then you would still have to clean that sponge with a weekly water change since the moss would just stick to the sponge.
i have a penguin biowheel HOB for a 50 gallon on my 20 tall, which is going to be pretty heavily planted. in my 10 gallon which only has moss for plants, i have a topfin 20
The floss should be the last thing the water goes through before entering the tank.filter floss- before or after filter cartridges? I heard they should go in before or else they get clogged easily but if im using flourite should i put it in before the cartridges?