2-Stage Filtration System hygger internal filter for a small fish tank provides mechanical and biological filtration to help keep the water clear and the tank healthy. The fine sponge catches fish waste and tiny debris while bio balls provide plenty of spacious areas for the colony of beneficial bacteria. No More Fish Get Suck up As an internal fish tank filter, this small filter is a fish-safe seamless design without any moving parts, so it can protect the small fish from getting sucked up. It would not suck the tiny fry into the filter and there will not have a heavy load of debris in the water because the biofilter with gentle water flow is great for fragile invertebrates, such as fry fish, betta, guppy, shrimp, and tetras. The internal filter is perfect for shrimp tanks, quarantine tanks, or fry tanks. Aerate the water for more oxygen The best small internal aquarium filter not only can keep the tank water clean but also agitates water by making bubbles. It slowly moves water around which is great for fish that love slow-flowing such as betta and guppy fry fish, etc. Low Maintenance Internal Filter You can replace the sponge with any brand of sponge, just cut to the size and clean the bio balls every two months. Replace partial bio balls every six months, and replenish only ⅓ at one time. Air Pump Driven Filter Like most sponge filters, the hygger small internal filter requires at least a 2w air pump & an airline (both sold separately) to run with. The convenient plastic chamber allows for quick and easy access to filter media maintenance or replacement.
