Low Acid Levels

birkesl

Well-known member
May 28, 2013
50
Washington, Il
So, after my first year of running my pool here in Illinois and subscribing to this forum it is all starting to make sense (sometimes it takes a while for me to grasp concepts without actually experiencing them). Here's what happened this year: I started out with acceptable ranges of everything but CYA (which was 90). Over the course of this year I've run through a LOT of pucks in my chlorinator. When it was hot (not very often this pool season), I had to add liquid chlorine on top of the pucks running my pump constantly in order to keep algae away. My pool is crystal clear now with just pucks and has been for nearly a month; however, my acid and TA levels have dropped like rocks and eyes are irritated when swimming (but man is it clear water). So, my overall understanding is that the pucks have lowered my acidity, lowered my TA, and raised my CYA (all bad things). If I fully subscribe to the methods shown in this forum I will be using only liquid chlorine, sampling more often, and not using pucks at all. I will need to remove about 1/3 of my total pool water before winterizing and then starting with fresh (well) water next year I will need to fully subscribe to the methods I mentioned in the last sentence. Make sense? Am I missing anything???
 

spidey07

Platinum Supporter
LifeTime Supporter
Jun 1, 2012
269
Louisville, KY
That's it. With the heavy puck use your CYA is likely much higher than 100. By "low acid levels" do you mean low pH? Can you post a full set of test results? Having your TA higher will help with the pH as you are aware the pucks have CYA which is acidic and will lower pH and TA over time. Both of which can be corrected easily with borax (raise pH) and baking soda (raise TA).

I'd be more concerned about CYA and FC levels to maintain a sanitary pool. If your CYA is over 100 you're going to have to drain more than 50% of the pool to get to the recommended 30-50 range.

FC/CYA chart
pool-school/chlorine_cya_chart_shock
 

uloset

Well-known member
Jul 11, 2013
58
Central New Jersey
Just on a technical note the pucks have actually raised your acidity, the lower the pH the higher the acidity the higher the pH the more basic. Everything else is spot on.
 

Bama Rambler

Mod Squad
TFP Expert
Bronze Supporter
LifeTime Supporter
Jun 22, 2009
23,626
SouthWest Alabama
Spidey gave you good advice. If by low acid levels you meant low pH, that's actually high acid level. 7 pH is neutral. Lower that 7 is acidic and higher than 7 is basic. We try to run pools slightly basic, as in 7.2 to 7.8 pH.

If you're close to closing, you can drain some water now and then drain whatever is required next season to get your CYA about 50 ppm.
 

aztony

Bronze Supporter
Oct 10, 2012
154
Maricopa, Arizona
I hope this is the correct forum to post this question. The issue I'm having is also a low cyanuric acid reading. Extremely low, like @10 or less, should be around 60, according to pool supply store I had test the water. This is 3 weeks in a row it has tested so low. The guy first thought I might have a leak causing it to be so low. I contacted the company that installed the pool. Their response was if there was a leak, I would have noticed a higher water bill. They said to get the acid level back up to where it should be and see what happens in a couple of months. If there's a leak, it should go back down. I went back to the pool supply store and the guy said to use a gallon of water conditioner and see how much that raises the acid level. I probably will need to add more but he wanted to see where the level was after adding the conditioner. That's where it stands right now. What's bothering me is even if we get the level back where it should be, what caused it to drop so dramatically in the first place. Any ideas or suggestions will be appreciated. TIA

Pool facts: SWP, 10,000 gals., inground, 3.5 years old All other levels on the last test where fine except for the acid @10 and the pH @8(a little high).
 

YippeeSkippy

Mod Squad
LifeTime Supporter
Jan 17, 2012
11,536
Evans, Georgia
birkesl said:
If I fully subscribe to the methods shown in this forum I will be using only liquid chlorine, sampling more often, and not using pucks at all. I will need to remove about 1/3 of my total pool water before winterizing and then starting with fresh (well) water next year I will need to fully subscribe to the methods I mentioned in the last sentence. Make sense? Am I missing anything???
Since you now understand the risks of using pucks and how they raise your CYA , I'm wondering if you can just use the winter's rain and snow to help you exchange your water a bit before spring? Do you cover your pool? Can you let the snow/rain fill it while you also backwash some out now and then?
 

danacc

LifeTime Supporter
Jun 29, 2013
269
Welcome to you, aztony!

Pool store results are sometimes inaccurate, and CYA is a test that they are more likely to get wrong than the others.

I recommend getting one of the recommended test kits: pool-school/pool_test_kit_comparison, and checking for yourself. Then you'll have reliable information and can make a solid decision on what to do next.