i use a 100 micron filter pad in my wet-dry, ive never had to clean bio balls in two years and theres still no debris in my bioballs
i find that 25 micron is most effective in a pressurized cansiter filter such as ones made by ocean clear and pentair aquatics, since water is forced through the media via powerhead instead of by gravity., extending its life between maintanence.
i find that 25 micron is most effective in a pressurized cansiter filter such as ones made by ocean clear and pentair aquatics, since water is forced through the media via powerhead instead of by gravity., extending its life between maintanence.