I got a new xp3 for my girls and I read that 1 liter of ceramic rings will work for 75 gallons of water. Is this right? I googled that 1 liter roughly equals 1000 grams most packs I've seen come in 500gram bags. Also can I leave the rings in the net bag or do you think it works best loose? Is it economical to make your own charcoal bags for your filter? Can I reuse polyfill if I just use it to filter tap water in an optional set up?
Any input for my first canister will be lovely, thanks!