Pool Opening Chemestry Question

[JamesW]

Can you do an fasdpd chlorine test, a new pH test and an alkalinity test? A low pH does not seem likely with your reported results and what you have added.

The pH test looks washed out. Can you describe how you did the pH test?

 

[pixpicker]

James W, not sure about your question. I just did the pH and alkalinity tests with the TF test kit as per the instructions. I will redo them now and post results.

 

[JamesW]

With an alkalinity at 110, it would be unusual for the pH to get too low unless something acidic were added. When I get results that seem unlikely, I retest.

 

[pixpicker]

Here's the retest results.

 

[JamesW]

I'm having trouble reading the pH test. I'm not sure what that is. With the TA at 110, I would think that the pH would be good to high, not low unless something acidic were added, such as cyanuric acid.

I think that I would wait until the fc went below 10 to get a better read on the pH.

 

[pixpicker]

Ok and thanks. So just let the sun bring down the chlorine level?

 

[JamesW]

Yes, just allow the sun to bring the fc down. Once the fc is below 10, recheck pH.

 

[pixpicker]

Today's test. Looks like I need to raise my pH. Any comments welcomed.

 

[JamesW]

Yes, it looks a little low. Try raising it just a little bit.

What is your current TA?

 

[pixpicker]

Yes, it looks a little low. Try raising it just a little bit.

What is your current TA?

TA is 90. Water is clear. PoolMath suggests I add 224oz of Borax to bring up the pH. Does that seem right?

 

[JamesW]

That sounds good.

 

[pixpicker]

Today's test revealed a pH of 7.5 and NO chlorine. The CYA is 38. I added 116oz of bleach and turned on the SWG to boost. Any comments?

 

[JamesW]

Test fc more often to prevent low/no fc issues. Raise cya to 60. Maintain fc/cya at 15% for a few days and do an overnight chlorine loss test to see if the low fc allowed any algae to start.

 

[pixpicker]

Worst day yet. Pool water is cloudy with a chorine level maybe at .75 and a pH barely 7. This is despite adding 3.5lbs of chlorine tabs to the skimmer and a gallon of bleach this week and having the SWG on boost for the past 24 hours. I also added 3lbs of baking soda. The cya is barely 40 after adding 4 lbs of stabilizer on Wednesday and 4 more yesterday. What am I doing wrong and what should I be doing?

 

[JamesW]

The tabs and cyanuric acid are the cause of the low pH. Raise the pH to about 7.4. Follow the Slam process as described in pool school. Use liquid chlorine or regular 8.25% sodium hypochlorite bleach. Test fc daily to make sure that the fc never goes below 7.5% of the cyanuric acid level.

 

[pixpicker]

Ok and thanks. I added the borax yesterday and will test the pH hopefully today. If that checks out I'll slam the pool as per the instructions. In anticipation, what's my best course of action if the fc starts falling dramatically?

 

[JamesW]

Once you finish the slam process, test the fc daily to make sure that it never goes below 7.5 % of the cya.

 

[jccams]

CYA can take up to a week or so to register once added. Don't add anymore until a week has gone by after your last addition, then check and go from there. To limit the FC level you have to maintain during the slam process you are better off having a lower CYA level.

 

[pixpicker]

I hit the grand slam this morning so I'll keep you posted. Test every 24 hours?

 

[JamesW]

After the slam is complete, test at least once per day until you get the fc to a stable level. Thereafter, test as often as needed to maintain a stable fc level.