Integrated Manual Fill ... Plumbed to Soft Water?

[Stoopalini]

My water softener loop passes right behind where our pool is going, and we're having a manual fill valve installed, which will fill through the water fall feature. The pool builder is suggesting I fill the pool with non-softened water, and also plumb the fill into the non-softened water line as well. They say if I use the water coming out of my water softener, it won't have enough calcium and will leech it from the plaster.

I was planning to fill with the softened water, and add calcium .. and have plenty of time to research and decide on that ... but for plumbing concerns, I'll need to make a decision fairly quickly on which line to tap into for the manual fill valve.

So what would be best to go with here?

 

[JimMarshall]

Your CH will creep up over time as you lose H2O to evaporation (which leaves behind things like CH) and then you keep adding additional CH via your tap water. I’d plumb the fill after your softener. This will slow the process.

furthermore, adding CH if you’re a bit low is way simpler/cheaper than what you have to do to lower CH if it is high (water change)

 

[Stoopalini]

Your CH will creep up over time as you lose H2O to evaporation (which leaves behind things like CH) and then you keep adding additional CH via your tap water. I’d plumb the fill after your softener. This will slow the process.

furthermore, adding CH if you’re a bit low is way simpler/cheaper than what you have to do to lower CH if it is high (water change)

That's what I was thinking.

So for the initial fill, how should I approach the filling process? Do I take a measurement of both the hard water and the softened water's CH, and depending on the readings .... choose the fill source.

And if it makes sense to use the soft water, do I add appropriate CH additive all at once (before starting the fill process) .... enough additive to result in the CH being a reasonable level when filling is complete ..... to prevent the fresh plaster from being leeched of calcium during the fill process itself?

 

[JimMarshall]

Getting a good measurement of the CH of both your softened and unsoftened water would be a great place to start.
It might even be the case depending on the numbers that you fill with a mixture of each?

You should be able to fill the pool first and then balance CH.

Unless you would have super acidic water, the type of damage you are speaking about won’t happen overnight.

 

[Stoopalini]

Makes sense. I just ordered a TF-100 kit, and will test when it arrives. Thanks for the input!

 

[BowserB]

Your water softener almost certainly has a bypass. I used that for the initial fill. Since then the autofill (which I use manually) adds soft water. Only after extended rain and overflow to drains do I every have to add calcium. As JimMarshal said, water evaporates, but calcium stays.

 

[Stoopalini]

Your water softener almost certainly has a bypass. I used that for the initial fill. Since then the autofill (which I use manually) adds soft water. Only after extended rain and overflow to drains do I every have to add calcium. As JimMarshal said, water evaporates, but calcium stays.

Thanks, good point. Although I actually have a spicket tied to non-softened water, very close to the pool; and could use that to do the initial fill without needing to mess with the softener's bypass.

I suppose the test results of the non-softened and softened water will drive the decision here though.