Chlorine in check - now on to PH/TA

[longinoa]

Did a new set of measurements today
FC 10.5ppm
CC 0ppm
PH 8.1 (measured by an electronic probe)
TA 140
CH 250
CYA 80
Salt 1400

Since Ive "fired the pool guy" and adopted TFP water has been super clear. Its been not nearly as much work as I thought and actually probably healthier for my pool equipment as Im actually emptying the skimmer daily
Ive only been adding chlorine to date and decided to start getting my PH in check as its been drifting up.

Since both PH and TA are high that means I need to use enough muriatic acid to drop to 7.2 and aerate right? I just put in ~1/2 gallon of 31.4 5% I generally run my twin waterfalls for 5 hrs both sat and sunday but I am thinking thats not nearly enough aeration is it? What is a decent proxy of how much aeration is enough, or is it just measure and see how it tracks?

 

[mknauss]

Lower the pH into the 7's. No need to aerate. When pH reaches 8, repeat.

 

[Bperry]

Did a new set of measurements today
FC 10.5ppm
CC 0ppm
PH 8.1 (measured by an electronic probe)
TA 140
CH 250
CYA 80
Salt 1400

Since Ive "fired the pool guy" and adopted TFP water has been super clear. Its been not nearly as much work as I thought and actually probably healthier for my pool equipment as Im actually emptying the skimmer daily
Ive only been adding chlorine to date and decided to start getting my PH in check as its been drifting up.

Since both PH and TA are high that means I need to use enough muriatic acid to drop to 7.2 and aerate right? I just put in ~1/2 gallon of 31.4 5% I generally run my twin waterfalls for 5 hrs both sat and sunday but I am thinking thats not nearly enough aeration is it? What is a decent proxy of how much aeration is enough, or is it just measure and see how it tracks?

Dont trust the electronic probes too much. They have to be stored and calibrated very carefully to stay accurate.

 

[longinoa]

ph just rises naturally?

 

[longinoa]

Dont trust the electronic probes too much. They have to be stored and calibrated very carefully to stay accurate.

While I did just calibrate mine I have healthy amount of suspicion on them. I have a hard time reading the ph test in the tf pro Im not color blind or anything just difficult to read the small gradiations.

 

[mknauss]

Don't commiserate over pH so much. Your CH is low so scale is not even a thought.
If the pH test has a purple look, add acid. If reddish, no worries. If yellow, you added too much acid last time. Test TA. If over 60 ppm, no worries.

pH rises naturally. Your fill water is high in TA. So no need to force it.

 

[AUSpool]

While I did just calibrate mine I have healthy amount of suspicion on them. I have a hard time reading the ph test in the tf pro Im not color blind or anything just difficult to read the small gradiations.

It’s taken me ages to be confident with the phenol red and comparator pH test but it shouldn’t be that hard with a little persistence. I always do FC and then pH. In your case with the FC at 10.5ppm the phenol red test will artificially look more purple, higher pH. When I have a FC above 10pm I use 2/3 pool sample topped up with distilled and run the test again.

There is a lot going on with the comparator and the colors on the FC side don’t help. I would take a photo of the comparator in front of a white background and edit out everything other than the pH side. That makes it easy to choose the right match. After a few times it gets easier to pick the best match without an edited photo.

I have a HM pH hand held but don’t use it much and never without calibration. I’m not confident with cheep calibration and storage solutions so I use Hanna which cost me more then the meter. The meter I don’t use because I’m confident with the phenol test now.

Having said that your pH is kinda ball park where we’d expect it to be and adjusting it to 7.6 is a safe approach. It will slowly creep up.

What is a decent proxy of how much aeration is enough, or is it just measure and see how it tracks?

There isn’t, and yes, testing is the best approach.

I’ve not read any literature or studies that quantify gas exchange with aeration, surface area to air flow modeling but we do know it does speed up the natural tendency of pH rise due to enhanced gas exchange.

A TA of 140ppm is not exceedingly high and easily managed by just adjusting your pH to 7.6 as needed.

If you do want to actively reduce your TA adjusting your pH down to 7.2 just before your waterfalls normally run will help to bring the pH up a little faster but its not absolutely necessary, your just taking advantage of what your have.

On the odd occasion that I lower my pH to reduce my TA my CSI never goes low enough for long enough to cause any concern and I actually want my pH to move slowly to reduce the amount of times I need to adjust it. I don’t want to speed it up and force it to increase faster.

 

[proavia]

A trick that works for some of us is to use 4 drops instead of 5 drops of reagent for the pH test.
This can sometimes make it easier to match the colors.

 

[pjt]

I have a hard time reading the ph test

A consistent background is key. To get good backlighting, hold the block in front of your computer monitor/tablet/phone with a blank white screen displayed. Also, try holding the block sideways or upside down. Sometimes that helps distinguish colors better. I also use two old hotel keycards to mask off areas and narrow down my decision.