New to BBB Method / New to the Forum

JeanZ1

Bronze Supporter
Aug 15, 2017
67
Newark/DE
Hi Redjeep,
It appears your ph/Alk has stabilized. You haven't had to add acid since 9/3 it looks like. I think you're over thinking the pH/alk thing. Measure your pH once a day. No need to measure again after chlorine addition (or any other addition, except acid of course). It's just extra data that mucks up the waters (no pun intended). Keep in mind as well that stability doesn't mean the number never changes, pH will change over time (within a couple/few days) even when pool is perfectly balanced, and will need regular adjustment.

The biggest contributor to a lack of precision (numbers all over the place) is inconsistency is sample size. Take care to make sure you measure the exact amount of sample every time. Using 11mls instead of 10 starts you off with a 10% error, not good. Just wanted to give you some food for thought. I know over time my measuring consistently every time has improved greatly and my numbers tightened up considerably. These tests are tailor made for the OCD crowd!

As mentioned previously, you also seem to have something else going on that is eating your chlorine, most likely algae. Your loss of almost 10ppm between 9/7-8 supports this, as does your earlier data with excessive chlorine loss. It looks like you need to SLAM. Keep in mind it is not a one time addition of chlorine but maintaining a high chlorine level over time (see FC/CYA chart) until the 3 exit criteria are met. It also has nothing to do with pH/alk, just coincidental.

The sooner you stop trying to tie these 2 issues together the sooner you'll get everything in line. They are completely independent.
 

redjeep61

Active member
Sep 1, 2019
34
Phoenix, AZ
Latest:

Test 12:00 9/8/19
FC - 4.5
CC - .5
Ph - 7.8
Alk - 70
CSI = 0.16 (pool math)

Test 19:30 9/8/19
FC - 3
CC - 0
CSI = 0.23 (pool math)

20:09 9/9/19 Add 11 fl oz of 73% CalHypo (Target FC 8)

Please focus comments on balancing Ph / TA. Waiting for Ph 8+ otherwise maintaining Chlorine with CalHypo just until box is used up. Don't need any more reminders about evil CalHypo. I know Chlorine consumption is not related to Ph / TA. For whatever reason, lets chalk it up to a mystery, as my Ph/TA rises so does my Chlorine consumption. For those of you up north your Chlorine consumption is much less than mine but your pool is not in the full AZ sun all day. There is no algae, my FC does not move all night, if any .5 when a dust storm comes through. Still getting used to the moving target for chlorine so if my FC falls below 2 it happens oh well, I SLAM and OCLT and move on.
 

redjeep61

Active member
Sep 1, 2019
34
Phoenix, AZ
Latest:

Test 12:30 9/10/19
Ph - 8.0+
Alk - 75

12:30 9/10/19 Added 38 fl oz of 28.3% muriatic acid (Target Ph 7.1)

Test 21:00 9/10/19
FC - 3.5
CC - 0

CSI = 0.4 (pool math)

21:30 9/10/19 Add 10 fl oz of 73% CalHypo (Target FC 8)
 

aeh0603

Well-known member
Apr 6, 2016
237
San Diego, CA
I know you asked for comments to focus on pH and TA, but your test results don't look concerning to me on that front.

I do have another thought on your FC consumption though. When I was looking at your numbers before I don't think I noticed that you are in Arizona and also keeping your CYA at 30. Since you say you passed the OCLT but are still having a big daytime FC loss I think you should try raising your CYA up to 40 or 50. This will protect your FC a bit more from the sun. Just make sure to follow the FC/CYA chart for the new CYA level.
 

setsailsoon

LifeTime Supporter
TFP Guide
Oct 25, 2015
1,593
Stuart/FL
Red,

I'm not getting the same results in Pool Math:

1568259797452.png

I've got about the same size pool as you but I live in S Florida and have a screen enclosure. I typically added liquid chlorine every other day and used about 2 ppm per day. Liquid chlorine additions increased pH initially and then reduce to the starting level (or pretty close). But pH did rise even without chlorine addition. This is normal due to aeration. Since you live in Marty's area I would expect you to have similar chemical usage at about twice his use since your pool is about 2x his. My pool was very stable for 99% of the time using liquid chlorine but I finally got tired of carrying the jugs and switched to swg a few months ago.

I hope this helps.

Chris
 

setsailsoon

LifeTime Supporter
TFP Guide
Oct 25, 2015
1,593
Stuart/FL
Red,
I know this can be frustrating especially to people trying to learn as they address issues after taking over a pool. I had very similar situation but not identical when I took my pool over. My wife was very leery and ready to hire a new pool service with any blips on the pool so I didn't have a lot of wiggle room to learn. I looked over all your posts and I'll summarize my comments:
  • pH seems to be the most difficult issue. pH is a log scale measurement so it can be difficult to control. A single unit increase or decrease means your acidity is swinging by a factor of 10. When you try to adjust to 7.2 instead of the recommended range you're actually causing it to swing more. Stick with the recommended ranges and it will help. pH rises naturally in most pools because the natural aeration that occurs at air interface on the surface and with water features and spa spillover. Without going into the chemistry the net effect of aeration is pH increase. Liquid chlorine will initially increase pH but this effect is reversed as the chlorine reactions in water proceed. If you test frequently and add acid before the chlorine reactions complete you are making pH swing unnecessarily. Also, any pH readings taken with FC over 10 are unreliable. FC above 10 interferes with the pH test. If you correct pH by adding acid at high FC levels you are making the pH swing unnecessarily. The pH readings are difficult to read as you get to 8 and higher. Some people are slightly color blind with the purple-red range so the reading can be inaccurate here. I have this issue so I use a digital pH meter. I believe a combination of all these factors are causing your frustrating swings. You can reduce the swings by following the advice of our experts and Pool School.
  • Testing frequently is OK but just don't over-react. I did exactly the same thing when I started. I learned a lot about my pool but headed the advice of experts to avoid too many changes in a short period of time.
  • Using Cal-Hypo isn't normally recommended because we like to only adjust one thing at a time. Our same logic works for tri-chlor. In your case the calcium was low and you had extra product on-hand so it seemed to make sense. But you live in an area where CH is very high in supply water so our expert was trying to help you avoid the problems this causes.
  • I noticed your calculated CSI seemed to disagree with Pool Math. If there is a problem with the way you're using Pool Math it could cause the swings as well, thus my comment with the picture of my results. If you can't duplicate the PM results let us know and we'll help you through this.
Everybody here is trying to help. TFP methodology works as a system. You can't really pick parts of it to implement or over-focus on just one thing. Our experts routinely help people quickly get control of their pool in way worse situations than you are dealing with. Marty and Allen are always successful with this.

Please take these comments in the constructive way they are intended. Good luck to you and I truly do hope this works out for you.

Chris