Raise Alk?

[beth83]

First full season of maintaining my own plaster pool. My ALK has been pretty stable all year and just now dropped to 50. Should I add baking soda? My CSI is too low even though the numbers seem OK. Can you see my chemistry results?

I'm also trying to plan on making sure my CSI is good, especially since I will be closing the pool in mid October.

 

[mknauss]

Why did you add acid two days ago? Your pH was in the 7's. No need.

I would wait to see if the pH will come back up to 7.8 or 8 on its own.

 

[beth83]

Why did you add acid two days ago? Your pH was in the 7's. No need.

I would wait to see if the pH will come back up to 7.8 or 8 on its own.

I have trouble telling 7.8 from 8 on the pH test. I've been adding acid when I think it might be between 7.8 and 8. The test only goes to 8 so I've been worried about it getting too high. The pH test is the most difficult for me to read.

Any recommendations to keep the pH from going too high? Will a high pH damage my electric heat pump?

 

[mknauss]

With a TA of 50, pH will not go too high.
The test sample should be of purple hue if pH is 8 or above.

High pH will have little effect on pool equipment if scaling is not an issue.

 

[pjt]

Should I add baking soda?

No. TA of 50 is perfectly fine. However, be judicious with MA additions.

For the TA test, are you continuing to add drops until there's no additional color change? Do you have a SpeedStir?

I've been adding acid when I think it might be between 7.8 and 8.

Don't.

Any pH in the 7s is fine. When your pH drifts into the 8s, add a tiny amount of MA (just enough to get you to 7.8-7.9)

The pH test is the most difficult for me to read.

A consistent background is key. To get good backlighting, hold the block in front of your computer monitor/tablet/phone with a blank white screen displayed. Also, try holding the block sideways or upside down. Sometimes that helps distinguish colors better. I also use two old hotel keycards to mask off areas and narrow down my decision.

 

[beth83]

No. TA of 50 is perfectly fine. However, be judicious with MA additions.

For the TA test, are you continuing to add drops until there's no additional color change? Do you have a SpeedStir?

I do have a speed stir. Tomorrow I will check alk to see about any additional color change.

Don't.

Any pH in the 7s is fine. When your pH drifts into the 8s, add a tiny amount of MA (just enough to get you to 7.8-7.9)


A consistent background is key. To get good backlighting, hold the block in front of your computer monitor/tablet/phone with a blank white screen displayed. Also, try holding the block sideways or upside down. Sometimes that helps distinguish colors better. I also use two old hotel keycards to mask off areas and narrow down my decision.

My pH test has 7.6, 7.8, and 8. The last two have similar hues of pink in my opinion. I do use bring sun at my back and I have a white fence that I face when I check.

 

[PoolStored]

With a TA of 50-80, your pH should be stable between 7.8 and 8.0. Let it be stable there, don't try to lower it below 7.8 when your TA is 50-80.

 

[pjt]

I do use bring sun at my back and I have a white fence that I face when I check.

A computer monitor or tablet with a blank white screen will give you a perfect, uniform backlight for assessing pH.

 

[beth83]

A computer monitor or tablet with a blank white screen will give you a perfect, uniform backlight for assessing pH.

I like your pH testing idea. I used my phone to verify but it looks like 7.7 right now. I wish my test went to 8.2 so I could feel better about it not being over 8.

I also tested alk again. I counted until there was no color change and got 60.

 

[pjt]

I used my phone to verify but it looks like 7.7 right now.

I would also call that a 7.7

With a TA of 60, your pH rise will be minimal and slow. pH will probably stabilize in the high 7s. You're looking great.