What to look for in primer/booster pump for watermaker ?

[OldManMirage]

I am putting together a small 3-4 gal/hr watermaker that fellow member Pizzazz detailed in his postings.

As an update to this Pumptec has recommended using a priming or booster pump.

What I am unsure of is what kind of specs am I looking for in this pump ?

I do know I want it 12 volt and I'm guessing I don't need a large pump. I would like it to be self-priming.

I found this on Amazon...
https://www.amazon.com/dp/B00DLKT4OO...=A3EBZ5HHZPL73

Should be sufficient, yes ?

[SailingHarmonie]

Poor choice. There are a lot of complexities to running two positive displacement pumps in series. The booster pump should be a centrifugal pump.

For size and ratings why not contact Pumptec? They a have good support reputation.

[scherzoja]

If you get a diaphragm pump, make sure it does not have a pressure switch; you don't want that pump to turn off while high pressure pump is running. Also, with a diaphragm pump, you need a bypass loop so that pump's excess water (water not consumed by the high pressure pump) has some where to go, back to the boost pump's intake.

If you get a centrifugal pump, you don't need a bypass because a centrifugal pump's impeller will just spin; however, with a centrifugal pump, you need to make sure it is below the water line. Remember, pumps are better at pushing than sucking, so keep the pump's intake hose length to a minimum.

[OldManMirage]

Awesome, I knew there was something I wasn't clear on.

And that is also a great idea to contact Pumptec, think I'll do that next week.

[sailorboy1]

if installing below waterline I recommend one of these

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

simple, water cooled, low power