Managing pH

[ptelgenh]

Just moved to a new home. Pool is about two years old. Fired the pool guy and am managing myself with a lot of help from this site! Thank you. This is my first post. Today's water test:

FC = 2
CC = 0
pH = 7.8
Hardness = 172
Alkalinity = 80
CYA = 51
Copper = 0
Iron = 0

I'm managing sanitizer with 12.5% liquid chlorine and pH with Muriatic acid. This is all new to me - last pool we owned was managed with Leslies powder power pro - ended up with algae, high CYA, etc, etc. You know the drill. The new pool gets a lot of direct sunlight. I'm adding chlorine 2-3 times a week and I lose about 1 ppm per day. I'm adding acid 2-3 times a week as it drifts higher due to the liquid chlorine (I assume). The pH drifts upwards at a rate of about 0.2 per day. So, I typically get the pH down to 7.6, then withing 2 days it's up to 8.0. Aeration: Spillway is used 1-2x per week, variable speed pump runs about 10 hours per day.

A few questions:

1. Is this all normal?
2. What is the suggested "order" or "timing" to add both the acid and chlorine - on different days? a specified # of hours apart?
3. do my set of circumstances change any of the recommended ranges? I currently use the pool calculator with TFP as the source

Thanks

 

[duraleigh]

1. Pretty much

2. Probably 30 minutes apart is all you need. You could actually add them one right after the other if you chose to....just not simultaneously

3. No.

Chlorine has no long-term affect on your pH. Your pH is rising because most pools do that naturally and the spillover contributes to that as well.

Have you lowered the pH to 7.2 to see what happens? Won't likely help with overall consumption but may not have to add acid quite so often.

You didn't ask but you need to increase your chlorine and keep it between 4-6 ppm per the FC/CYA chart up in Pool School.

 

[Patrick_B]

Welcome to the forum!

First, you need your own test kit. If you are going to manage your pool, a test kit is crucial.

Your Chlorine needs to come up, so see the proper amount as per the Chlorine CYA chart. With 7.8 pH you can adjust afterward. Wait a few minutes at most and add acid. Your loss of 1 PPM/Day is pretty darn good with full sun. Spend some time in Pool School with the ABC's of Pool Chemistry to start, and then all you can absorb from there. The pH rise from bleach is temporary, as the reaction and breakdown of it is a net acid process.

Edit: Looks like Dave beat me to it, sorry.

 

[ptelgenh]

Thanks for the quick replies. I do have my own test kit - Taylor K2006. And I will try the suggestion to bring pH down to 7.2. If I do that, I assume alkalinity will decrease as well. It's at 80 now, how low can it go until I need to be concerned?

 

[duraleigh]

Your test results look like pool store results, hence the suggestion by brushpup to get your own kit. You should ALWAYS trust your own testing over pool stores.

You can find normal ranges for all parameters (Including TA) by reading "The ABC's of Pool Water Chemistry" up in Pool School