As far as my filter, it's the aqua-tech power filter. It's a 3- -stage filtration for healthier fish and cleaner water. The first stage of the AQUA-Tech filtration is mechanical. The blue polyfiber pad that is integrated onto the EZ-Change Filter Cartridge screens out dirt and debris as water passes through. The second stage of the AQUA-Tech filtration is chemical. The activated carbon that is in the EZ-ChangeTM Filter Cartridge removes dissolved waste and cleans the water of odors. The third stage of the AQUA-Tech filtration is biological. The BIO-Fiber that is included in each AQUA-Tech Power Filter provides additional surface area for beneficial bacteria to grow and thrive.