Before use, soak the Bio-foam in aquarium water for 5 mins.
During maintenance, always rinse the Bio-foam with drained out aquarium water only. No tap water or hot water should be used at all.
When re-using the Bio-foam, do squeeze the foam in the water to remove all trapped air bubbles. This will keep the filter stay submerged.
Suggest replacing the bio-foam every 6 months, to ensure the filtering effect as well as the growth of the nitrifying bacteria