I have had a terrible time getting the proper filter set up in my tank. First I had a HOB filter which came with my tank and the cascading water sound from the unit back into the tank kept me awake all night. Next I purchased a Fluval internal filter. It is very quiet but wasn’t keeping the water clean enough. Next I bought a canister filter only to come home from work the second day I had it to find it had lost its prime and wasn’t working. My criteria for a filter was that it be quiet, efficient, and low maintenance. I bought another HOB and put it on last night. I was able to sleep through the night with it. However, this morning it is now making a noise it didn’t last night. It is from the lid vibrating against the unit. When I take it off the noise stops. Is there any reason I can’t operate the unit without the lid? It is the Aqua Clear Power filter. Any other suggestions for making it quiet or another type of filter I haven’t tried would be welcome. I don’t have the room under my stand for the wet/dry filter or I might have tried that. Thanks