Question on PH

Wicked

Well-known member
May 19, 2012
61
0
#1
Since I got my test kit and testing PH/CL daily and weekly for other things I notice my PH goes up from 7.5 to 7.8 in about a week - then i add muratic acid to lower and then it rises. Thoughts?

Numbers from 06/11

PH 7.5
FC 4.5
CC 0
TC 4.5
TA 60
CH 380
CYA 45

Today:

PH 7.8
FC 3.5 (SWG on 40% running on low speed for 6 hours a day - gonna bump it to 50% as I want to stay in the 4-5 range)
CC 0
TC 3.5
TA 60
CH 380
CYA 50

Is it normal for PH to rise that fast?
 

chiefwej

LifeTime Supporter
TFP Guide
Jun 12, 2011
3,219
0
Tucson
#3
That may be perfectly normal for your pool SWG and aeration can both cause pH rise. Normally low TA helps buffer it, but at 60 you are already very low. Borates would also help buffer pH rise. But in the end you would still use as much acid, just have to add less frequently.
 

Wicked

Well-known member
May 19, 2012
61
0
#4
I do have a built in spa that overflows to the pool - obviously this is happening 6 hours of the day along with SWG aeration.

So you feel this is a normal increase with these variables?

Best course of action just a weekly does of acid?

Thanks!
 

jblizzle

Mod Squad
LifeTime Supporter
TFP Expert
May 19, 2010
41,193
4
Tucson, AZ
#5
Since your TA is already on the low end ... sounds like you will just have to continue adding acid. The overflow and SWG are just going to keep raising it unfortunately.

Posted with Tapatalk ... sorry if I sound short ... hate typing on phone :)
 

Wicked

Well-known member
May 19, 2012
61
0
#6
thanks guys. since this is my first pool and I just received my test kit a couple weeks ago - I dont have any history or experience to compare too. So ill chalk this up as normal and report back in future test!

Shooting for 4-5 on the FC sound about right? From what I read my CYA should be bumper with an SWG - Im just concerned that Leslie always said I had 90-100CYA and when I test is always about 50. Guess I need to learn to trust my test :) I even give it to my wife and tell her to fill it and she gets the same number without me telling her or her even knowing what she is testing :) so definitely an unbiased tester!!
 

linen

LifeTime Supporter
TFP Expert
Jul 30, 2010
8,649
0
48
Twin Cities, MN
#8
Wicked said:
Shooting for 4-5 on the FC sound about right? From what I read my CYA should be bumper with an SWG - Im just concerned that Leslie always said I had 90-100CYA and when I test is always about 50. Guess I need to learn to trust my test :)
Minimum FC level for 50 ppm cya and a swg is 2 ppm (from poolcalculator.com), so you are running a little high. CYA of 50 ppm is lower then most people run for the swg, recommended levels is 70-80 ppm for swg.

Wicked said:
Im just concerned that Leslie always said I had 90-100CYA and when I test is always about 50. Guess I need to learn to trust my test :)
Typically new users get higher than actual readings. You do need to trust your readings since pool stores typically get this one wrong. If it helps, here are the cya extended test kit directions: http://www.troublefreepool.com/extended-test-kit-directions-t25081.html#p206397
 

BoDarville

LifeTime Supporter
TFP Expert
Jun 5, 2012
3,843
2
DFW, Texas
#9
Wicked said:
I do have a built in spa that overflows to the pool - obviously this is happening 6 hours of the day along with SWG aeration.

So you feel this is a normal increase with these variables?

Best course of action just a weekly does of acid?

Thanks!
Wicked:

I also have a spa that overflows into the pool. Even with a chlorinated pool (non-SWG) my pH tends to drift up, which is normal due to the aeration provided by the waterfall. During the swim season, I target a pH of 7.5. When it hits 7.6, I add a dose of MA as calculated by the Pool Calculator to get it back to 7.5. I test pH daily, so I am administering a dose of MA 2-3 X per week. I test TA weekly and adjust if needed.

BTW, that's some good looking clear water in your pool pic!
 

RaviePoolGirl

Well-known member
Nov 5, 2011
54
0
44
American Canyon, CA
#10
I too have a SWG and overflow from spa to pool. I have been adding 1 cup of MA daily. I don't like my pH to get up to 7.8. I try to keep between 7.5-7.7. Hard to tell what it is over 7.8 and my CH is high, so it's better to keep it lower for me.
 

Wicked

Well-known member
May 19, 2012
61
0
#12
linen said:
Wicked said:
Im just concerned that Leslie always said I had 90-100CYA and when I test is always about 50. Guess I need to learn to trust my test :)
Typically new users get higher than actual readings. You do need to trust your readings since pool stores typically get this one wrong. If it helps, here are the cya extended test kit directions: http://www.troublefreepool.com/extended-test-kit-directions-t25081.html#p206397
Good info. Quick question. The kit I got just came with a bottle with a label on it. It says fill to bottom of label with pool water then to top of label with CYA regent. Is there a more accurate measurement to be used? I.e. 7ml pool water 7ml cya agent?

Thanks