I was reading the recommended levels and just was curious as to why you want TA to be 100-150 when using trichlor tablets?
Thanks!
Why you want higher TA with trichlor tabs?
- Thread starter Jdaher
- Start date
I was reading the recommended levels and just was curious as to why you want TA to be 100-150 when using trichlor tablets?
Thanks!
svenpup
LifeTime Supporter
This is a great example of how at TFP we don't just shoot for some arbitrary range recommended by test strips or pool store. Understanding the effect allows us to adapt to the specifics of our circumstances.
TA tends to push pH up, so the higher the TA the more tendency for pH rise.
Tri-chlor pucks are highly acidic and therefore drive down pH and over time reduces TA. In this case it is beneficial to keep TA high since it will slow the effects of the pucks driving pH down.
Conversely, SWG systems tend to drive pH up due to the aeration they produce. In this case it is beneficial to keep TA low since it will slow the effects of the SWG driving pH up.
TA tends to push pH up, so the higher the TA the more tendency for pH rise.
Tri-chlor pucks are highly acidic and therefore drive down pH and over time reduces TA. In this case it is beneficial to keep TA high since it will slow the effects of the pucks driving pH down.
Conversely, SWG systems tend to drive pH up due to the aeration they produce. In this case it is beneficial to keep TA low since it will slow the effects of the SWG driving pH up.
If TA gets too low, then pH becomes unstable. If pH crashes, that is goes below the minimum testing range of 6.8, you won't know how low it actually could be. Might be 6.9 or 5 or 4 or 3, you won't know, it all looks like 6.8. At low pH you risk harming metals in the pool equipment. And of course if you are damaging metals, you sure as heck don't want to swim in that!
In my pool I noticed pH instability at TA of 50 to 60. One time I'd test and pH was lower than normal, then I'd test again and it was higher than normal. I decided that TA > or = 60 was the minimum for my pool. As my tap water has high TA, it is pretty hard to get my pool TA that low but a lot of rainwater and/or use of trichlor can do it. When I go on vacation, if TA is very low I will increase it a bit to compensate for what the trichlor tabs will do to the TA while I am gone. No need to go all the way to 100 but I will move it from 60 up to 80 or 90, should it be that low. I always do test to know so I can do what is needed.
In my pool I noticed pH instability at TA of 50 to 60. One time I'd test and pH was lower than normal, then I'd test again and it was higher than normal. I decided that TA > or = 60 was the minimum for my pool. As my tap water has high TA, it is pretty hard to get my pool TA that low but a lot of rainwater and/or use of trichlor can do it. When I go on vacation, if TA is very low I will increase it a bit to compensate for what the trichlor tabs will do to the TA while I am gone. No need to go all the way to 100 but I will move it from 60 up to 80 or 90, should it be that low. I always do test to know so I can do what is needed.