New Pool - PH Question

Jan 14, 2019
6
Baton Rouge La
#1
Hello all. is it normal for PH to rise to 8+ every 2 days or so on a new gunite pool(2 months old)? I have to add between 30-40oz of 20 baum acid every couple days. They turned it over to me 2 weeks ago and I am struggling to keep the PH below 8. I think I may be overtesting right now(every day) but I am afraid that if I let it go for a week it will be above 9+ PH

My test this morning- Taylor 2006
Current temp 68
Crystal clear - no visible issues
FC 5 . SWG just started working due to warmer temp. I lowered the setting temporarily
CC 0
PH 8+ looked a little pinker than 8 - 2 drops lowered it to 7.4
Alk 80
CH 280
CYA 20
Salt 3600
Taylor test booklet told me to add 40.6oz for 23000gal so I did. Should I use the booklet or Pool Math?

Any guidance would be great. Thank you.
 

mknauss

Mod Squad
May 3, 2014
12,217
Laughlin, NV
#2
I would not lower your pH below 7.8 as your CH is on the low side and that keeps your CSI at near zero. So keep adding MA every few days lowering your pH to 7.8.

I suggest using PoolMath for calculating your additions.

Rising pH is typical for a new plaster install. Over time your TA will drop a bit more and your pH will begin to stabilize. Takes a while, so keep monitoring your pH.
 
Jan 14, 2019
6
Baton Rouge La
#6
Hi Allen
I have waterfalls but they are on a timer and only turn on Saturday-Sunday. No spa. I read that the waterfalls will bump up the PH. However not sure how much is too much. It seems to be a fine art that I’m trying to learn as best I can.

Marty, I’m going to keep a close eye on it and just add enough MA to drop to 7.8 every 2 days for now.

it’s pretty cold so hasn’t been used at all. I’m concerned the weather warms up soon and the kids start using it. Balancing 7.8 is going to be tough since there isn’t much wiggle room.

Should I add some calcium to be able to balance to 7.6 or 7.4?

Thank you
 

mknauss

Mod Squad
May 3, 2014
12,217
Laughlin, NV
#7
As I assume a significant portion of your fill water will be rain water, it would be a good idea to raise your CH to above 300 ppm.

If you use tap water for fill water, what is the TA and CH of that fill water?
 
#11
I will test the ph of the fill water this afternoon, but I don’t have a automatic filler. Just a hose, I haven’t needed it yet.

Hi Marty, yes I am using pool math. My size calculations maybe off? I was told 23000 gallons.

17x32 4’ shallow to 5’ deep end
17x6 tanning ledge 8” deep
That doesn’t take into account the stairs or the x4 4’ benches

Seems about right to me. Dunno. If that is right then it’s just as you said with a new pool.

Thank you
 
May 3, 2014
12,217
Laughlin, NV
#12
You can actually use adding MA for pH reduction to narrow down your volume. Next time you add MA, use PoolMath to tell you how much you need to add to lower to X.X pH. Add the MA and circulate the pool for 30 minutes. Test pH again. Use that number to see what volume pool is needed to get that result with the amount of MA you added.

Be sure you are using a current TA value in PoolMath when determining how much MA to use to lower your pH.
 
#14
Thank you Allen and Marty. I will try the Ph test to narrow it down. I was thinking smaller also but they said no.

I wasn’t aware that the MA reacts so fast to get a good reading in 30 min. I was waiting 24 hours between tests. Maybe that’s what confused me if the Ph went up again in that time.?
 
May 3, 2014
12,217
Laughlin, NV
#15
The liquid chemicals you add (MA and liquid chlorine) disperse and mix rapidly. As long as you mix the water with the pump and depending on pool shape, the brush a bit in certain areas, you can test for their impact in 30 minutes or so.