Yeah, it is 30" deep!! I really wanted the depth because this is/was going to be a FOWLR, mainly Seahorse tank. The height is great for them....a chore for me.
I don't think the DYI thing is the issue. Before I added the skimmer, the height of that carbon thing was about 10.5", and it had LR rubble in it as a bio filter/diffuser. I removed it completely to add the skimmer and let it run. The noise was the same as now. My over-flow however was louder, and produced more bubbles. I modified the original design and put it in, directly on/over the SEDRA pump and everything went back to normal....relatively quiet, except the airline on the skimmer. I am going to try the "pill box" silencer that Joel posted, that looks productive.
