Quick review:
I bought a Jebao DC-6000.
Not new. Roberto had a spare, with no controller, so was a good deal.
First impressions : Seems good.
Super quiet, lots of flow!
At least with no head. Not hooked up yet.
I have not measured the flow exactly either.
It has a slow start feature. It takes 30 seconds to turn on fully, slowly ramping up.
Not sure if that is good or bad yet.
It has a nice analog control input. 0-5V = 0-100% pump.
Normally the supplied speed controller goes there, but probably use my Arduino.
CONCERN: The manual says "Fresh water only".
Hopefully that is leftover from the original pond pumps. The manual is rather poor,
and has some grammar issues.
They do call the pump "Marine"
It is mostly plastic, with a few stainless parts. But a slight worry they used poor quality stainless.
ISSUE: Pipe fittings.
The pipe fittings are 1.25 inch. But they are not standard NPT.
Instead, they are NPSM.
Meaning, the threads are straight, and not tapered.
You can put a normal female pipe fitting on, but it needs lots of silicon, or may leak.
Clearly the intent is really for hose fittings, which are supplied.
Power supply is mediocre.
It is a GVE, which is namebrand for china. About 80% efficient.