My borax level is low, and my TA is high. A thought occurred to me: can I lower TA faster by lowering pH with muriatic acid, wait for a few hours, then add borax to increase pH, then repeat? Aeration seems to take a long time to raise pH.
Pretty close, but not quite. I always remember them like this......From what I understand, lowering the pH with MA will lower the TA, raising the pH with borax or baking soda will also raise the TA.
Borax raises TA by half as much as pH Up, but it still raises it. In fact, borax raises TA by slightly more than Muriatic Acid lowers it, assuming you end up at the same pH (though the extra amount of TA that borax adds is borate ion, not carbonates). Borax is a base and any base raises both pH and TA. Lye (sodium hydroxide) would also raise both the pH and TA. So it is inaccurate to think that borax has little effect on TA. The see-saw most absolutely happens if you add Muriatic Acid and then add borax. You cannot lower TA that way at all. You have to outgas carbon dioxide and aeration at low pH speeds that up.duraleigh said:Lower pH - use muriatic....TA also comes down
Raise pH - use borax.....it has little effect on TA
chem geek said:Borax raises TA by half as much as pH Up, but it still raises it. In fact, borax raises TA by slightly more than Muriatic Acid lowers it, assuming you end up at the same pH (though the extra amount of TA that borax adds is borate ion, not carbonates). Borax is a base and any base raises both pH and TA. Lye (sodium hydroxide) would also raise both the pH and TA. So it is inaccurate to think that borax has little effect on TA. The see-saw most absolutely happens if you add Muriatic Acid and then add borax. You cannot lower TA that way at all. You have to outgas carbon dioxide and aeration at low pH speeds that up.
A better way of looking at this is that all acids lower pH and TA while all bases raise pH and TA. pH Up (sodium carbonate) is a combination product that is identical to a pure base (lye; sodium hydroxide) with baking soda (sodium bicarbonate) so ends up raising TA about twice as much as a pure base so roughly twice as much as borax.
Richard320 said:Why are you worried about high TA? Does the pH jump a lot? Are you dangerously close to scaling? It will come down eventually if you just maintain the pH. Every pool has its own personality. Some will have a pH flatline at 100 TA, some will battle the pH until TA is 60. If it's not causing any problems, why mess with it?