Confused/question

[B-ridge]

i recently bought a cobalt mj400 thinking it would have enough power to pump water from my saltwater mixing drum into my sump for automatic water change. The site says max 23" head space/room. I placed the pump in drum which is a regular 55 gallon drum used to hold water and what not. The pump couldn't pump the water all the way out to go into my sump
Now my question is or shall I say where the confusion begins is how are the small ato pumps like the one that comes with the smart ato or the one I had for a tunze osmollator able to pump the water out of the same drum and into my sump but the mj400 can't?

 

[Joeganja]

Maximum head pressure is 29" where the innovative marine aqua gadget pump is max head pressure at 5 ft and the mj1200 max head pressure at 69" it seems like your pump is pumping water a distance and height it cannot be strong enough so I would advise a stronger pump especially if your pumping water vertically.

 

[B-ridge]

Yes it's about 2-3 feet in bottom of drum. Then up maybe another 2-3 feet before the hose loops over into the tank