Runaway pH

[MLock]

Hey everyone, this might be a common issue, but I'm struggling to use the TFP search and only get hot tub results. I've used this forum for years to help me with my pool, but I'm a new hot tub owner and have a struggle.

When I go to bed, every night, I've worked throughout the day to get myself to:

pH: 7.5
TA: 90-100
FC: 2-3
CYA: (new tub, so I'm currently at about 10 and rising as I add dichlor)
CH: ~400

When I wake up in the morning, every reading is exactly where I left it, except:
pH: >8.2

So I add muriatic acid, get pH down, then sometimes (but not every day) have to add washing soda to get TA up over 50 because of the muriatic acid. Then I go to bed with good pH and overnight it freight trains to where the color in my Taylor kit is almost purple it's so high.

Help a newbie, please...

 

[JoeSelf]

Let your TA go down. That will slow your PH rise. I went down to 50 and PH rise slowed. I also use AquaClarity which helps with PH rise.

 

[ajw22]

The washing soda you are adding is undoing the work on the pH.

Just manage the pH and let the TA find its equilibrium.

PH TA Relationship - Further Reading

www.troublefreepool.com

 

[MLock]

Super helpful stuff, folks. My pH is pretty stable now at 7.6. My TA is settled around 35-40. Everything I read says keep it at at least 50. Should I be wringing my hands over this?

 

[Krulligo]

For my tub, I need to have my TA around 50 ppm with 50 ppm borates added to maintain a stable pH of 7.6-7.7. At this point I rarely add muriatic acid due to how stable the pH is. 35-40 is a bit on the lower end. I would at least try to be in the 40-50ppm range. Have you tried adding borates to lock the pH in? Also, its ok for your pH to be slightly higher at 7.7 or even 7.8 is fine too.

 

[MLock]

Hi Krulligo, yep, my borates are currently at about 45ppm. I used boric acid - perhaps I should bump that up a little bit to 50 or 55ppm.

 

[Methuselah]

Super helpful stuff, folks. My pH is pretty stable now at 7.6. My TA is settled around 35-40. Everything I read says keep it at at least 50. Should I be wringing my hands over this?

How sure are you on the TA? If it's one drop on a drop test it could be 45-50 which is acceptable (where min likes to be when my ph gets stable).

 

[Krulligo]

Another tip, make sure to have all your air valves for your jets set to closed position when spa is not in use. Your spa will do cycles throughout the day and if you have your air valves open, it will cause more aeration which will rise pH faster.