I can’t figure out why my PH keeps rising. I lowered my PH to 7.2 a week ago, my TA is 120 and today my PH is back to 8.4. We have had no rain and I do not have an auto fill. My CYA is 80, CH is 325. Any suggestions would be greatly appreciated.
High PH
- Thread starter Radred39
- Start date
Lower your TA to 50-60 and it should help. Also you may find it easier to just keep it at 7.6-7.8. Assuming your pool is new? New plaster will raise the pH for a good while.
- Jan 4, 2016
- 5,288
- Pool Size
- 44000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
Nice to meet you via TFP 
Our approved test kits can't measure pH of 8.4, but that's not all that important. The pH is high and gets high quickly because the TA is high.
Repeatedly reducing pH with muriatic acid will also reduce TA. Getting down to around 80 will make a big difference.
You can do this over time, or it can be done quickly via this procedure: Lower Total Alkalinity
Our approved test kits can't measure pH of 8.4, but that's not all that important. The pH is high and gets high quickly because the TA is high.
Repeatedly reducing pH with muriatic acid will also reduce TA. Getting down to around 80 will make a big difference.
You can do this over time, or it can be done quickly via this procedure: Lower Total Alkalinity
How do I lower my TA, by lowering my PH? Not sure if my other reply posted but the TF-100 instructions say to keep TA between 100-120.
I meant the TF-100 says to have the TA at 100-120 for a manually chlorinated pool. But I was told to lower my TA to 50-50Nice to meet you via TFP
Our approved test kits can't measure pH of 8.4, but that's not all that important. The pH is high and gets high quickly because the TA is high.
Repeatedly reducing pH with muriatic acid will also reduce TA. Getting down to around 80 will make a big difference.
You can do this over time, or it can be done quickly via this procedure: Lower Total Alkalinity
If you are using trichlor sanitizer (tabs) than the total alkalinity might be better at that level but TFP recommends using bleach/liquid chlorine to sanitize your water because your stabilizer level Will keep building up if you use those tablets too much. Take a look at the TFP pool school article for more information.
I don't use the tabs anymore, I switched to Calcium Hypochlorite 70%. I will be draining and starting over in the spring but trying to get educated so I can control my levels after refill.
- Jun 1, 2018
- 13,592
- Pool Size
- 26000
- Surface
- Vinyl
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
The tf100 instructions do say that but it does no harm to lower TA below 100 to help buffer ph rise especially in a plaster pool.
Dose to 7.0 /7.1 every time ph rises to 8 & the ta will lower overtime or you can follow the guide @needsajet linked to do so more quickly/deliberately. It also explains how ta & ph are married.
Your PoolMath logs only show a few acid additions & no test logs so not sure where your ta started out at but currently it has plenty of room to come down.
Basically the lower the ta the slower the ph rise & vice versa. Some pools have very little/slow ph rise at a ta of 100+,
some like it lower. As stated above as low as 50/60 is acceptable.
Your mileage may vary based on your csi needs.
Note* If you are using cal hypo to chlorinate be sure to keep an eye on ch levels as well.
See
Recommended Levels
Dose to 7.0 /7.1 every time ph rises to 8 & the ta will lower overtime or you can follow the guide @needsajet linked to do so more quickly/deliberately. It also explains how ta & ph are married.
Your PoolMath logs only show a few acid additions & no test logs so not sure where your ta started out at but currently it has plenty of room to come down.
Basically the lower the ta the slower the ph rise & vice versa. Some pools have very little/slow ph rise at a ta of 100+,
some like it lower. As stated above as low as 50/60 is acceptable.
Your mileage may vary based on your csi needs.
Note* If you are using cal hypo to chlorinate be sure to keep an eye on ch levels as well.
See
Recommended Levels
- Jan 4, 2016
- 5,288
- Pool Size
- 44000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
See "recommended levels" above. TA of 100-120 would simply require more frequent pH testing and adjustment. TFPC recommended levels are the best levels to use. You'll see many other recommendations elsewhere.
Because it is a test kit and all test kits come with the same boilerplate recommendations.
The best TA level is the level at which your pH is most stable. Since that's the kind of answer that comes with a few of caveats and limitations you'll not find it in any manual.
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