Storage tank vs second pressure tank

[Wise12u]

In an effort to reduce cycles and increase cycling time would it not be more beneficial to add an auxiliary storage tank rather than a second pressure tank? At that rate a 25 gallon aux tank would give you 25 gallons vs 6 gallons that a 25G pressure tank would.

If the aux tank is pressure rated (meaning it is ok to fill with pressurized water, still not having a blatter/diaphragm), would the pressure tank take care of the pressure switch and the aux tank provide additional volume and draw down gallons?

I'm new here, not a plumber but just applying my layman's logic that I know can be fallible.

 

[RetiredInGueydan]

A 25 gallon auxiliary storage tank has 0 draw down gallons and only flows through the 6 gallons from the pressure tank. A CSV would be a better method to solve your cycling issues.

 

[Sponsor]

 

[Reach4]

A storage tank would not be pressurized, and it would cause a need for a a separate pressure pump to provide pressure to the house. If your well will not run out of water, just use the bigger pressure tank or the CSV.

Now can you can in some cases use a second pressure tank to make the two capacities add, but that can cause funny effects if there is a large pressure drop between tanks while the pump is running. A short or big-diameter path/pipe between the tanks can let this work. A CSV can slow the flows as the pressure reaches the cut-off pressure, and allow a longer path between.

The funny effect to avoid is the pressure switch cutting off before the farther tank is up to pressure. Then that second tank serves as a load after the pump cuts off, possibly reducing the pressure enough to make the pump kick on again. Even if that does not happen, the pressure drops significantly after the pump turns off.

 

[SuperGreg]

I have two pressure tanks, one after the final ultrafilter because it requires a clean water rinse after backflushing. I have four total filters in between the two tanks, and it takes a while for pressure to equalize. The second tank never reaches the max pressure (60 psi) ever. I do get very long pump cycles, and generally it does not trigger again after equalizing.

This setup used to feed the whole house, but now the output goes to a float valve in a cistern tank, that then feeds the house through a CSV and small pressure tank.

 

[John Gayewski]

I think the best setup is s big pressure/ bladder tank with a cycle stop valve is the best setup.