PH Rise in Pool

[Calleblanc77]

My pool is about 8 months old and i constantly find my PH rising. I live in Houston, TX and the outside Temps are about 95 -100. I feel like my numbers are all in line but don't really know why it doesn't seem to want to stabilize. I thought it would stabilize by now as i would like to keep the PH in the range around 7.2 and 7.4 for my CSI to be balanced. I can get it there by adding acid but then it seems to drift up in the next day or two. I am using liquid chlorine and not chlorine pucks. I do have a waterfall which i never run and i do have a hot tub which has a spillover into the pool which i thought may be contributing to this PH rise due to aeration. I have a good Taylor K-2006c test kit and test CL and PH every day in the evenings. Any advise or tips would be greatly appreciated.

CL 1.5
PH 7.7
AK 80
CH 300
CYA 35
Outside Temp 98
Pool Temp 94
Pebblesheen Pool

 

[jaduck]

I think it can take a year or better for your pH to stabilize in a new gunite pool. I would also recommend that you get your FC up as it is too low for your CYA.

At a CYA of 40 you should target a FC of 5 and never let it drop below 3.

 

[pooldv]

Yes, it will take a year or longer for the plaster to cure and PH to stop rising. Change the CH and TA target numbers in poolmath to see if lowering TA or raising CH will help the csi. I just.played around in poolmath and you are fine with ph at 7.7. Just keep lowering ph to 7.2 when it gets to 7.8 by adding muriatic acid. This will slowly lower your TA and help reach equilibrium.

Use the Pool School - Chlorine / CYA Chart to set your chlorine level.

More on chlorinating your pool here, Pool School - ABCs of Pool Water Chemistry