I'm sure I'm using more than necessary filtration but my aquaclear and sponge filters( the coops silent nano ones) does extremely well for my 50
If it's an air pump for a sponge filter, try putting the pump on a towel. Also be sure the air hose isn't touching anything. That can cause vibration also.
I have my air pump sitting on a piece of filter sponge to prevent the vibration. I also use a cannister filter and haven't noticed it being loud at all.
I have a 55 gallon aquarium and Im using the Penn plax cascade elite on my planted tank.
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