I run a Sicce 3.5 on my son's 75G / 25G sump. Note the Sicce (along with others) have a mechanical shutter on the intake to adjust flow- generally once it's dialed in, no need to change. My thinking was, why mess with a DC controller that sacrifices efficiency and reliability for the sake of adjustability on something that needs to be adjusted 2, maybe 3 times over the life of the pump?
I would have agreed the 3.5 seemed a bit much for a 75G when we started the tank, but that became a non-issue when we went to a dual return. I can't be happier with the flow, in a pinch you could even use it to replace a powerhead. FWIW, we run one click closed (about 85-90% capacity).
The majority of the noise in my case came from the plumbing vibrating, not from the pump- once I figured that out and made adjustments, the return pump is quieter than everything else making the water slosh around.
I would have agreed the 3.5 seemed a bit much for a 75G when we started the tank, but that became a non-issue when we went to a dual return. I can't be happier with the flow, in a pinch you could even use it to replace a powerhead. FWIW, we run one click closed (about 85-90% capacity).
The majority of the noise in my case came from the plumbing vibrating, not from the pump- once I figured that out and made adjustments, the return pump is quieter than everything else making the water slosh around.