Help with TA

[Jeff piper]

If this was you hot tub, what would you do and why, so I can understand the logic for the future. See picture for specs
THE pic might not be clear enough to read so the #s for pool math are as follows
2
12.5 % chlorine
1200 liter water
PH 7.3- goal 7.5
CH 150 goal 150
FC 3 goal 5
CC 1
TA 20 goal approx 40
Borate 50 goal 50
CYA 29 goal 29
Temp 38*C
In pool math the confusion lies between adding baking soda or washing soda or both
Could you please help to educate
Thank-you
Jeff

 

[pooldv]

Add baking soda to raise TA to 50. Use baking soda because it raises TA without raising pH much.

More here about what chems do, Pool School - Recommended Pool Chemicals

 

[Richard320]

Baking Soda raises TA without doing much to pH
Borax raises pH without doing much to TA
Washing Soda raises both pH and TA.

Your pH is between 7.2 and 7.8 so just change the target to match the now. Nothing needed.
You do need some baking soda. I'd target 60 TA myself which isn't much: 120g by weight or 100 ml by volume.

The 1 CC is worrisome, though.... did you by chance just remove the cover immediately before testing? If not, you might want to go a bit higher on FC and leave the cover off tomorrow so some sunlight hits it.

 

[ant 83]

In my experience, baking soda will raise both TA and PH.

The rise in PH is delayed however, until the water aerates some. This can happen fast if the air jets are run with the cover off. It will also happen whenever the cover is off and there is water movement.

Small amounts of baking soda can be added daily, and the PH will rise over time sure as the sun.

 

[pooldv]

Baking soda raise TA. Higher TA pushes up pH.

 

[Jeff piper]

Yes just took the cover off a few minutes before testing, thx for the info