I don't see a fan in the box to suck air in or push air out where the compressor is. Ideally you want to have ambient air flowing over the compressor, the direction the fan on the compressor is blowing air. If you put a lid on it to enclose it, you will smoke the compressor very quickly due to the heat generated.

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3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).