I'm going to bump this up with some new info and questions. My DCP-10000 has been running silently for several weeks now, no issues at all. Still not sure it moves the water claimed but I'm happy with it.
Second thing, I've been talking with Fish Street about the bigger models, the manual lists an 18000 and 20000 size. They had no idea bout the 20000, said it will not be coming to the US, however the 18000 they already have, they just haven't had a chance to update their site yet. They said it can be special ordered, it is about $180 if I recall correctly.
So my situation, I'm looking for a pump to push water up 5', over 5ish feet, then up again another 6'. At the top of the tank it splits via a "T", then over the top and into the tank, all with 2" pipe. The 18000 is about 4750 gph, any guesses what it would be putting out at roughly 15' of head? I'm looking for somewhere around 1500 gph.
I haven't seen any flow charts for these pumps, of any size, so I'm not sure how well they handle the pressure.