Review on 🐠 AQQA Aquarium Electric Power Sponge Filter - 3W/5W Submersible Foam Filter for Saltwater and Freshwater Fish Tank by Keith Ostby

I bought two 3W filters. Both perform well in terms of filtration and water flow (29 gallon tank, light stocking) - in fact I would have liked a little less flow for an aquarium. But one of them is silent, the other has a noticeable rumble. The hum can be heard throughout the room (similar to the hum of an air pump) even when fully submerged in water. I feel significant vibrations from a noisy pump. A loud hum is also present when you hold it underwater without touching the glass or substrate. The loud pump is louder than the Eheim air pump. The quiet pump runs silently, except for bubbles (which can be easily turned off if desired). At the top of the outlet is an air inlet for venturi effect ventilation. This causes a gurgling noise (similar to any pump with a venturi effect port). If you don't need ventilation, you can glue a short piece of air pipe (1 cm) to the other end (DIY cap). This pump will not fit in a 20m substrate tank unless you mount it diagonally. The 3w pump says it's rated at 70 GPH.