"Gene" wrote

The only reason that I want a 2nd smaller pressure tank
is to keep the submergible pump in the well from
constantly shutting on & off. The plan for the 2,000+ gallon
poly holding tank is to draw down to say, 500 gallons,
then the submergible kicks on & fills it up to the 2,000+ limit.
This way, the submergible is not constantly switching on & off.
I really do not care what the above ground pump does, it's
easy to replace & service. It will probably have a ~100 gallon
pressure tank and be a 60psi with a large rate of flow.

Gene

You are forgetting about the water that is stored in the well. Your pump
moves that water as the recovery water 'runs' into the well. A 6" well has
1.47 gal/foot of water. With a screened well the pump is usually set at the
top of the screening but.... that depends. You really need to know what
youre doing with this or you are going to have future problems.

You really don't want to pump 1500 gallons all at once. You want to store
water in the cistern, so you should use water and then replace it after say
50-100 gals. Saving start ups of a pump is a good idea but, there has to be
a balance in the system and the well is key to all this effort. So you don't
want to screw up the well or the water qaulity by over pumping the well by
constant large drawdowns. IMO, you need to know the pumping level of the
well. That's pumping until the water level stops falling, then you set the
pump 10-20' below that level or... you set the pump according to the
screening. I'm not very familiar with screened wells but you don't set the
pump 10-20' off the bottom as you can/should in a rock bore well.

I suggest a float switch to control the sub pump and a safety float switch
to control the house pump so it doesn't run dry. You need to know
proper/correct size sub pump for in the well and you don't size it based on
the recovery rate of the well. You size it based on the total head into the
cistern. Size isn't just hp, it is gpm and then the proper hp to do the job.
And that gpm has nothing to do with the recovery rate gpm of the well.

Gary
Quality Water Associates