Just check on a couple thing, testing

[Titan7]

New pool almost at 90 days of water.

Current test:
FC 8
Ph 7.8
Ta 70
Ch 400
Salt 3100
Temp 87
CSI 0.06

Dropping PH to 7.3 lowers CSI to -.041

Seems to drift up to 7.3 7.8 every couple days, normal?

@ 7.8 the CSI is just under +1. I thought the goal is to be at zero in a perfect world.

So should I leave it to drift up to .1 or keep dropping ph to get CSI at - .04 and let it drift up again?

Thx

 

[PoolStored]

Seems to drift up to 7.3 7.8 every couple days, normal?

Yes.

So should I leave it to drift up to .1 or keep dropping ph to get CSI at - .04 and let it drift up again?

You are a bit in a corner with CSI. You'd like to have it slightly negative to avoid scale in the salt cell.

With your TA already fairly low, lowering TA to 60 only buys you about -.06.

With low pH, it will tend to rise, which you will add acid, lowering TA even more.

This will work in the short term, but don't let your TA go below 50.

About the best thing you can do is lower your CH, but that requires water replacement. You also likely have high CH fill water.

Have you tested the CH and TA of your fill water?

 

[Titan7]

Okay more test results:
Fill water
TA= 180
CH=250

I just did another CH test and I am at 500ppm

How did this go from 250 to 500 in 85 days?

 

[PoolStored]

Evaporation and autofill. CH does not go away with evaporation. In AZ, with high CH fill, and evaporation, CH can rise quickly.

Do you have a water softener? Many of our members in the SW plumb their autofill to softeners to avoid rising CH.

 

[proavia]

Are you using a SpeedStir or similar electronic stirring device?
The stirring device will greatly improve testing accuracy.

A CH result of 400 one hour ago and now a CH result of 500 is testing inconsistency.

Our high CH and TA fill water, coupled with high evaporation rates, will cause CH and TA to rise.
With a fill water CH of 250, your pool CH will rise by 250 or more every year.
Consider adding a water softener line to your autofill to keep CH in check.

Your linked PoolMath logs show a date from 6 years ago.

 

[Titan7]

400 was from a month ago, never saw CH rise like this on my old pool so I assumed it would be more consistent, wrong.

Yes using speed stir, it 500, did the test 2x. No way to add softer line so I guess I am doing water transfusions every year.

I will just keep csi like 0 to -.03

 

[proavia]

400 was from a month ago, never saw CH rise like this on my old pool so I assumed it would be more consistent, wrong.

Yes using speed stir, it 500, did the test 2x. No way to add softer line so I guess I am doing water transfusions every year.

I will just keep csi like 0 to -.03

Ok - CH 400 from a month ago. I was going by your statement of current - as in today.

Are you holding the reagent bottles perfectly vertical?
Don't force the drops off the tip - let them fully form on the tip amd drop from their own weight.
Dispense one drop per second.

A rise in CH of 100 in one month is excessive.

CSI range should be 0.00 to -0.30 to minimize SWG scaling.
With a CH of 500, you will actively need to monitor and adjust pH several times per week to keep CSI in range.

 

[Titan7]

Did the test again, 19 drops it turns light blue, 20 makes it a little more blue 21 drop does not change color, it’s between 19 and 20 drops it’s a subtle change. I will just keep CSI 0 to -0.30. Once CH gets so too high that I can’t maintain CSI I will do a transfusion of water or partial drain each winter.

 

[casiokid]

I’m also in the southwest and my CH went from 0 after a reverse osmosis in March to 600 three months later. Heat, evaporation, and the Colorado river autofill water will do that!

I keep my TA at 60 and my pH at 7.6 to combat the scale.

For me, the reverse osmosis will probably be an annual procedure although I know others on the forum maintain CH at or above 1000 with no issues.