【Protect shrimp and fish】 The filter cotton is filtered in several layers, which completely prevents shrimp and fish from being sucked in. 【Prevents clogging】 It can prevent large foreign matter from being sucked into the filter system and blocked. 【Used】 Suitable for aquariums, to protect shrimps and small fish and to clean the water quality. 【High quality】 Our aquarium filter cotton is made of high quality sponge with good filter effect 【Increase the oxygen content of the aquarium】 The principle of biological filtration using multi-layer filtration to cultivate high-density nitrifying bacteria to achieve the effect of increasing the oxygen content of clean water