The latest test results...

[pooldv]

If PH isn't happy with TA at 80 it will continue to lower anyway as you add acid to keep lowering PH. TA as low as 60 is fine and even 50 sometimes. Try to keep your CSI negative all the time. Negative is better. I try for -0.1 to -0.2 ish.

Sometimes CYA disappears in cold water over winter. Either it is heading south for the winter or some coldwater bug is eating it. I don't know for sure but it happens fairly often so keep an eye on it.

 

[Jpolsen]

pH/TA balance still puzzling

A couple weeks ago I lowered my TA from 140 down to 60 now using MA and aeration. Now with TA in better check, My pH still rises at a pretty good clip...from 7.3 on the 12th to 8.1 this morning. What gives? Is the TA still too high possibly or perhaps too low? I'm not sure what a normal rate of rise is for balanced pH. Expert advise needed.

 

[tim5055]

Re: pH/TA balance still puzzling

What was the rate of rise before you lowered the TA? Do you have water features that are adding to the rise?

I would target pH in the 7.6-7.8 range instead of going as low as7.3

 

[Jpolsen]

Re: pH/TA balance still puzzling

The rate of rise was slightly faster with the higher TA, but it hasn't slowed appreciably since lowering...granted, I was aerating to raise pH during the TA lowering process. No aeration now, I only have three returns and each is pointed to shoot just below the surface. They're causing ripples, but don't seem to be enough to be considered aeration. Just trying to move the surface water.

 

[pooldv]

How old is your pool? It can take up to a year for plaster to fully cure and for the PH to settle down.
Do you have an SWG?
What is the TA and PH of your fill water?

60 is not too low but doesn't need to be any lower. It is possible that the returns rippling the surface could the PH to rise.

 

[Jpolsen]

I'm not sure of the age of the pool, but it's not new. The surface is actually a bit rough in some spots...could this have something to do with it?

No SWG.

Im going to test my fill water, but I haven't used it in several weeks, so I doubt that is the culprit. I'll test it again today and lower pH to 7.5 and see what it does over the next week or so. Returns are also pointed lower to create less ripples.

***EDIT***
fill water is:
pH - 8.0
TA - 130

After testing the pool water again, I get:
FC-6.2
CC-0
pH-7.9
TA-60

Yesterday, when I tested my water, it was on the heels of adding approx. 140oz of chlorine the previous evening that I needed to use since I've had it for a few weeks. That may have skewed the pH test results.

 

[Jpolsen]

Sorry for still having questions about this pH thing...I just want to learn all I can about it. I'm still puzzled. Tested today and here's what I observed:

FC-3.6
CC-0
pH-7.8 (up from 7.4 just 5 days ago)
TA-60

Still a couple questions:
Pool school says if TA is too low, the pH will swing around wildly. What does that look like? Does that mean it might possibly read lower than a previous day during these swings? My pH continuously climbs...never lowers.

After adding MA on the 21st to lower pH to 7.4 from 7.9, it has risen to 7.8 as of today. Does that look to be a normal rate of increase, or should I try my TA at 50?.

Again, sorry for beating this seemingly dead horse, I just want to know all I can about this. You've all been a great help so far!

 

[JoyfulNoise]

Too low a TA is less than 40ppm. You're fine. You can try to lower it to 50ppm but you might need to consider adding 50ppm borates.

But here's your problem - you're lowering your pH way too much with each acid dose. Target a pH of 7.6 and stop there. There is no reason to go lower than that and, when you do, you're only making your pH rise worse. When you lower your pH below 7.5 you drive you bicarbonate buffer towards producing CO2 which makes the pH rise faster.


Sent from my iPhone using Tapatalk,16k gal SWG pool (All Pentair), QuadDE100 Filter, Taylor K-2006