They work well but are slightly noisey and IMO way over priced for what you get. I run all of my Hydro5 foam filters with $11.00 MA-600 dual outlet air pumps by million air. I can't honestly think of a reason to spend more money on a piece of equipment with basicly the same design...All of ours are VERY quiet unless you place them on a resonant serface and then all you need to do is slip a block of foam under it.
I've compared the MA-600 to just about everything out there and they are as reliable...powerful and as quiet as pumps costing many times more.[/quot
Thats not to bad. I can always just construct a box with foam pad walls and a vent in the back for cooling and air intake. that should quiet it down a little