Grundfos SQF centrifugal vs. helical?

zzrider

So we have a 4", 115' deep well that we're going to be using for off-grid residential and small-scale agricultural purposes on our Florida homestead.  I plan on using a Grundfos SQFlex for input power flexibility.

It appears that, given the relatively shallow well, I could use either a 3" 11SQF-2 helical or a 4" 25SQF-7.  If I'm reading the charts right, it seems like the 25SQF-7 is the obvious choice because it has about double the GPM output of the 11SQF-2.  

Is there anything I'm missing in this comparative evaluation?  Is there any reason the helical would be a better choice?

JRHill

You don't give enough information about your needs. What is your confusion between the two pumps, their specs, the power consumption and your water needs? What's your well guy say?

My experience is well guys don't want to say much so they won't be on the hook... Kind of like when they show up and ask "OK, Where do you want it?" You say "Where would it be best?" Whey say anywhere. They might be better with pump selection especially for a more expensive one.

When I had my well dug I had them come back and sink an 11SQF-2 and cap it at the column. I built the rest of it from stuff available here at the store. I bought the monitor and the IO switch. You don't need any of that expensive stuff but the IO101 is cool to convert from DC to AC in a heartbeat just by connecting the power. No mistakes.. Frankly I don't use the Grundfos controller anymore. I'll make you a good deal on it. I run the pump off of a standard well pressure switch. No muss or fuss. There is also a precaution of people using the CU201 with the pressure signal and it didn't shut down, blowing lines. That pump can make a huge amount of pressure at 150' depth.