Is it really time to replace water?

[StogieC]

How high is really too high for CH? Or should I just replace water now before it becomes a bigger job?

CH 500
TA 120 (Working on lowering, See PH)
PH 7.2 (Was 8.2+ this morning, 7.6 yesterday)
CYA 50
Salt 3500
FC 13 (Holding a little high until CC back to zero)
CC 0.2

SWG failed last week. Replaced and working well again but we picked up a just few spots of black algae. They are dying off quickly.

 

[ajw22]

CH of 500 is manageable. Folks in the Southwest manage CH over 800. Monitor your CSI and use other chemicals you can more easily adjust like pH and TA to keep CSI below 0.

 

[KurtinTUS]

My pool is going into it's third southern Arizona summer with a CH now at 625. Expecting to go through a lot of acid to keep the CSI under control. This Fall I'll do a drain/refill.

 

[duraleigh]

PH 7.2 (Was 8.2+ this morning, 7.6 yesterday)

How are you testing? pH doesn't move like that....unless you are making Borax AND acid doses you are not telling us about.

 

[StogieC]

How are you testing? pH doesn't move like that....unless you are making Borax AND acid doses you are not telling us about.

That's just with doses of muriatic acid to bring the pH down. I'm hoping that lowering the TA will help to stop my pH from climbing. The pool is 634 sq ft of surface area and the waterfall has been running... I assumed that the aeration was contributing to the pH rise, but this pool has always been "acid thirsty". I alternate between using the K1000 that came with the TF-100 and the K2006 for testing. I'll get another pH test this morning once the sun comes up.

 

[duraleigh]

Still, your pH swings are too dramatic. The correct way to control your pH and TA is.....

Lower pH - use muriatic....TA also comes down
Raise pH - use borax.....it has little effect on TA.
Lower TA - acid and aeration method....see Pool School
Raise TA - use baking soda....it has little affect on pH

I would suggest targeting your pH for 7.6 or so and your TA around 60-80. Please review carefully how to manage those two parameters.

Sorry to hi-jack your question about CH so back to it. CH 500 in Florida is pretty unusual. Do you know the CH of your fill water?

With over 50 inches of rainfall annually (no CH) and fill water usually less than 200 ppm, do you have any idea how you got to 500? Are you using granulated powder (Cal-hypo) to chlorinate?

In the long run, CH 500 is quite manageable as noted above but we shoulds find out how you got there to avoid it in the future.

 

[StogieC]

pH this morning is still at 7.2 I'll check TA in a bit.

CH was at about 200 right after the pool was built three years ago. The contractor added calcium chloride (Robelle 2825 Calcium Plus, I still have the bucket) to bring CH up to 300, then again on their last checkup visit a month later to bring CH up to 400. I was told at the time this was to help the surface cure properly. Pool math logs show that CH continued to climb but has been stable at 500 for about a year. I usually test pH and FC/CC every other day during pool session, CYA, TA, and CH every other week. During the winter, I generally don't test unless somthing looks wrong with the water.

The good news is that I don't seen any remaining algae.

 

[StogieC]

pH 7.4
TA 80

 

[duraleigh]

It appears your pH has stabilised some. It should slowly drift upwards but not fluctuate wildly like you reported 4 days ago.

With the rainy season soon starting if Florida, you will likely have excess water into the pool and can pump some out, thereby reducing your CH by refilling with rainwater. Probably letting it go down to 300 is a good idea.

What is the CH of your fill water?

 

[StogieC]

My fill water CH is only 70.

Today:
pH 8 (it was 7.4 ~ 40 hours ago)
TA 80
FC 10.5 (I know this can throw off pH reading a bit but FC was 10 when I read 7.4)
CC 0 (Yay!)

 

[duraleigh]

1. With a fill CH of 70, you should NEVER have a problem with increasing CH so you have to figure out how you ever got to 500. You must have been adding CH either through excess doses or using a lot of Cal Hypo (granulated chlorine) for you Chlorine needs.

2. Your pH rise is wa-a-ay too fast. Are you running a waterfall or a fountain? What is the pH of your fill water? Are you testing pH with the TF-100 test kit?

 

[StogieC]

For the earlier test today I used the K-2006. I added some acid right after that test. I just retested with both the TF-100 and K-2006 and they show a pH of 7.5 and 7.6 respectively. The .1 difference is only due to the different scale of the two comparators.

The waterfall is usually off and has not been on since Sunday. But, the circulating water constantly agitates the surface and I run the pump 12 hours per day. It's also usually a bit windy here and the pool is not enclosed. My fill water pH is on the high side right now at 7.8 and we last added water on Saturday.