"Gary V. Deutschmann, Sr." wrote in message ...
Manufacturers ratings are based on an unrestricted flow with little to
no resistance from the piping.
In other words, they use very large pipes for the size of the pump
outlet. Normally more than double the size of the pump outlet!

This is kind of misleading for the custommer, who usually
expect the pump rating at 4' match the plumbing system he
has at his fish tank.

I have had longer life and better results using the low end price
range potted pumps, than I have with the more expensive separate
motor pumps.

That is what I am confused with... People are running very
expensive pumps but in my comparison QuietOne was just as
good as LittleGiant for the 1/3 price. Less space taken in
the cabinet, less electricity used to do the job, less heat
generated overall... And on top of this you say you have
better experience with this kind of pumps than with real
inline ones...

We also now use these little potted pumps in commercial hi-viscosity
pumping situations. The majority being Maxi-Jet 1000's. They consume
less electricity, last longer, and we can buy 5 of them for the price
of one standard line pump of the same output rating.
On really heavy liquids, we run two pumps back to back, one feeding
the other to keep the flowrate up where we need it for our commercial
purposes, and they still draw less electricity and last longer than
the original pump designed for the purpose.

In our case, the end bearings decompose from the fluids we are
pumping, but a gross of these bearings only cost about 18 bucks. So
we replace them once a month during cleaning, whether we need to or
not. The O-rings don't seem to be affected.

MaxiJet 1000? Did not know they make it... We have MJ900 and MJ1200
available for the fish hobby. Is the MJ1000 somewhere in the middle?
What is its electricity consumption? I find MJ900 much more efficient
than MJ1200 comparing watts used to flow in gph. So for free powerheads
it is much better to have water moving with three MJ900 than two MJ1200.
I have listed my findings about powerheads efficiency in November last
year on this group:
In this comparison MJ900 is almost twice more efficient than MJ1200
hawing index Flow/Watts 27 when MJ1200 has it only 14.75...