When I got mine I hooked it up and immediately noticed a loud, chopping noise from the Accela pumps. It had to be turned off at night as it was too annoying - even with the door closed.
I had a Red Devil SP3 pump from another skimmer project laying around. I removed the accellas and built a manifold using parts from Lowes. I have since built a now manifold it using PEX 3/4" tubing and CPVC and PVC parts also from Lowes.
The results were night and day. The SP3 produces way more foam with smaller bubbles. The micro bubbles that were horrible from the original pumps are now completely gone. The pump is near silent with only a minor hum and the air sucking noise is unnoticeable. The foam production is way better with dry skim mate now possible.
I had the original CPR Bak Pak back in the mid 90's but ditched it because it was loud and mediocre.
Just sharing. It is now overkill for my biocube, but I like having an oversized skimmer.