Aqua One 59w Wool Pad - 550 UFO - 2 pack ( one complete change)

The 59W is Aqua One's recommended top filtration layer for the UFO 550 aquarium. A pack of two is provided and these are superb at trapping debris and solid fish waste leaving the following foam and Bio Noodle layers to deal with the toxic Ammonia that yor fish produce. The 59W polymer pads should be disgarded once full and brown in appearance. Change once per month for best results.