Replacement Filter Pads for SUNSUN/AQUATOP HW-304B CF500 HW704B Aquarium Filters 16pc (12 Fine + 4 Coarse)

FITS: SUNSUN HW-304 B/ HW-404 / HW-704 AQUATOP CF500 Canister filter Grech GW-304 Perfect HW-304 Polar Aurora 525gph UV Features: Provides both mechanical and biological filtration. White fine pads filters out fine particles allowing for clear water. Blue coarse pads traps most visible particles without restricting water flow also serves as a host for all beneficial bacteria. (Blue pads can be reused after rinse) DIMENSION: 8.5" (L) x 8.5" (W) x 0.75" (H) INCLUDES: 4 Blue coarse pads 12 Fine white pads Sponges maintenance tips: The sponge will need to be rinsed every time it becomes dirty, about once every 1 to 4 weeks. It’s helpful to reserve the beneficial bacteria by washing the sponge gently with water from the fish tank instead of tap water. After 6 to 12 months’ usage, the micro holes of sponge is gradually clogged by the tiny debris, the beneficial bacteria won’t have as much living space as before. That’s when the sponge filter starts to lose its efficiency. So it is also recommended to replace the sponge once 6 to 12 months or when the sponge gets worn out.