Progress finally, or The TA battle...

[steveinaz]

Didn't make much progress yesterday:

FC=5.5
CC=0
PH=7.5
TA=120ppm (started at 130ppm--drifted up 10 from day before)
CYA=95ppm (retested this to verify)
CH=680ppm (tested this twice yesterday to verify)
Water temp=86

I used a total of 6 cups of muriatic yesterday evening, trying to break that magic 100---I'll do some measurements this afternoon to re-check. Waterfall had my PH from 7.0 to 7.2 in about 2 hrs, so I covered the pool and called it a night at around 7:45pm.

[waterbear]

TA=120ppm (started at 130ppm--drifted up 10 from day before)
Actually, the resolution of this test is 10 ppm so you really have the same result as the day before
CYA=95ppm (retested this to verify)
Still would not lose sleep over this with a SWG in AZ!
CH=680ppm (tested this twice yesterday to verify)
This test is tricky at best. If you are not allowing enough time for the titrant to react or using a magnetic stirrer then it is very possible to overshoot the endpoint, particularly when the CH is high and the titration is taking a long time. I noticed that before you had 710 ppm. Just call it 700 ppm. Next time you might want to try a 10 ml sample. 10 drops of calcium buffer, and three drops of indicator. Then every drop of titrant is 50 ppm CH. When your CH is as high as yours 50 ppm resolution is fine!
Water temp=86

I used a total of 6 cups of muriatic yesterday evening, trying to break that magic 100---I'll do some measurements this afternoon to re-check. Waterfall had my PH from 7.0 to 7.2 in about 2 hrs, so I covered the pool and called it a night at around 7:45pm.

Persistence! Lowering TA sometimes seems to hit a plateau, Keep up what you are doing and you will reach your goal.

[steveinaz]

Yep, I'm in it to win it this time. The hammering will continue this evening!

[steveinaz]

CH of my fill water is 120ppm, I tested it this morning. I think a aprtial drain will be worth the effort. Since I won't be dealing with the added complication of new plaster, dropping TA after re-fill should be a litte easier, right?

5.5 more cups of muriatic last night, TA down to 110 (uncorrected for CYA). I may have finally broken the plateau. Beating on it again this evening. The waterfall really helps with aeration, It brought me from a pH of 7.0 to 7.3 in about 2.5 hrs last night, running full pressure.

[waterbear]

CH of my fill water is 120ppm, I tested it this morning. I think a aprtial drain will be worth the effort. Since I won't be dealing with the added complication of new plaster, dropping TA after re-fill should be a litte easier, right?

Next question, what is the TA of your fill water? You will need about a 50% replacement to get your CH in range from around 700 ppm. You might even need a bit more than that.

[steveinaz]

Fill water:

TA=170ppm
CH=120ppm

New numbers this morning:

FC=6
CC=0
TA=90 (uncorrected)
PH=7.5
CH=680
CYA=90
Salt=2600
Water tmp=83 degrees
CSI= -.19 (balanced)

BEGIN CHAPTER 2, metal stain removal...

[waterbear]

Fill water:

TA=170ppm
CH=120ppm

New numbers this morning:

FC=6
CC=0
TA=90 (uncorrected)
PH=7.5
CH=680
CYA=90
Salt=2600
Water tmp=83 degrees
CSI= -.19 (balanced)

BEGIN CHAPTER 2, metal stain removal...

After you do the stain removal, if you do a water change to lower your Ch you will be removing much of the iron tainted water from your pool and reduce the risk of restaining. Untill you do you will need to add a maintenance dose of sequestran weekly to monthly.
Bad news is, once you do the water change you will have to lower TA again! (And also adjust, salt, CYA, etc.)

Too late now but, IMHO, the best way to do all of this would have been the stain removal, water change, and then lowering of TA.