Should Tap CH Equal Pool CH?

[CPM10V]

I recently tested the CH level in my pool & the fill water at source ( pool fed from exterior hose bib, city water). Note we had about 2” of rain over last few days.

Results:
Pool: 1350
Hose bib/fill: 375

I know the pool value is real high, but wonder if the two values should be relatively close to each other?

 

[ajw22]

CH accumulates in the pool as water evaporates.

When you add fill water it adds CH that stays in the pool.

So over time your pool CH climbs until you drain the pool and refill it and then pool CH will equal tap CH.

 

[CPM10V]

CH accumulates in the pool as water evaporates.

When you add fill water it adds CH that stays in the pool.

So over time your pool CH climbs until you drain the pool and refill it and then pool CH will equal tap CH.

Thanks! I suspected that was the case but wanted to make sure.

 

[proavia]

Where in Phoenix?
City water or well water?

375ppm CH is pretty high in our area. I would expectto see around 225-275 from the tap.

Are you using a SpeedStir (or similar) for testing?
Are you holding the reagent bottles perfectly vertical and allowing the drops to fully form on the tip? Drops should be dispensing about one every second and never foreced off the tip (squeezing the bottle too hard).

If your CH is over 1000ppm, a full drain/refill is in your future - but wait until fall, its too hot now.
If you could use softened water for your autofill, it would help keep CH within suggested range.

In PoolMath, turn on "Track CSI" in the app. CSI should be kept in the 0.00 to -0.30 range it minimize calcium scaling.

Fill out your signature with pool, pool equipment (including manufacturers and model numbers) and test kit info.
This assists us in providing help specific to your pool without having to ask each time.

https://www.troublefreepool.com/account/signature

 

[JamesW]

How often do you test calcium?

I would recommend every two weeks to keep an accurate track.

Do you ever use calcium hypochlorite?

What is the CSI?

What is the water temperature?

Turn on CSI tracking.

 

[CPM10V]

Where in Phoenix?
City water or well water?

375ppm CH is pretty high in our area. I would expectto see around 225-275 from the tap.

Are you using a SpeedStir (or similar) for testing?
Are you holding the reagent bottles perfectly vertical and allowing the drops to fully form on the tip? Drops should be dispensing about one every second and never foreced off the tip (squeezing the bottle too hard).

If your CH is over 1000ppm, a full drain/refill is in your future - but wait until fall, its too hot now.
If you could use softened water for your autofill, it would help keep CH within suggested range.

In PoolMath, turn on "Track CSI" in the app. CSI should be kept in the 0.00 to -0.30 range it minimize calcium scaling.

Fill out your signature with pool, pool equipment (including manufacturers and model numbers) and test kit info.
This assists us in providing help specific to your pool without having to ask each time.

https://www.troublefreepool.com/account/signature

I’m in the northeast part of Phoenix by Mountain Preserve.
City water.
Yes using the speedstir but not administering the reagents as detailed as you list, I will retest using the method you provided.
I’m planning on a complete renovation of pool within another year so was trying to avoid drain/refill. I don’t have any complaints with water appearance, looks great.
I have home softener and planned on connecting to future leveler.

 

[mknauss]

At your pool CH level, get some distilled water and cut your pool water 2:1 with distilled water. Then do the 10 ml test and multiply the results by 3. If you really had 1350 ppm CH, likely you would have widespread scale on all surfaces.

 

[proavia]

I’m in the northeast part of Phoenix by Mountain Preserve.
City water.
Yes using the speedstir but not administering the reagents as detailed as you list, I will retest using the method you provided.
I’m planning on a complete renovation of pool within another year so was trying to avoid drain/refill. I don’t have any complaints with water appearance, looks great.
I have home softener and planned on connecting to future leveler.

Check the tap water again using the method I outlined. Be meticulous in how you hold the bottle and let the drops fall. It may make up to a 100ppm difference in the tap water test. If the tap water test comes in lower, the pool water test should also - maybe a few hundred lower or more. Don't rush - and use the diluted method @mknauss suggested.

 

[CPM10V]

How often do you test calcium?

I would recommend every two weeks to keep an accurate track.

Do you ever use calcium hypochlorite?

What is the CSI?

What is the water temperature?

Turn on CSI tracking.

Check the tap water again using the method I outlined. Be meticulous in how you hold the bottle and let the drops fall. It may make up to a 100ppm difference in the tap water test. If the tap water test comes in lower, the pool water test should also - maybe a few hundred lower or more. Don't rush - and use the diluted method @mknauss suggested.

Well after testing as you described I got:
City tap: 275
Pool: 1250-1300

The pool test was still the standard non-diluted 10 ml via Speedstir.

The color change from pink to blue includes a period of transition to a violet color.

So looks like my technique was off since the city value is closer to what it should be as you mentioned but the pool value I’m still unsure on.

what is the process for the diluted test as @mknauss mentions? Combine 10ml pool sample with 20 ml distilled water, then pour mixture into Speedstir beaker? How much of each reagent is then used due to dilution? Then multiply drop count by 3? Thanks for the help.

 

[mknauss]

Add 20 ml distilled to 10 ml pool water. Pour off to 10 ml. Do the normal test procedure. Multiply the results by 3.

 

[CPM10V]

I tried the diluted method & wound up with similar results, 18 drops * 3 for value of 1350. Since the test/value of tap water seems reasonably accurate for the area then the value for pool can be assumed to be accurate as well? Thanks again for help, looks like I’ll be adding a water softener to pool fill when renovating.

 

[mknauss]

Sounds correct. Soft water is a great method to simplify your pool water chemistry maintenance.