pH--soda ash vs baking soda

[cygnusecks]

My PB also said that, if you have a spa spillover, you can crank up the spa returns so that you get a lot of spillover, which will aerate the water better than the "dribble-over".

[waterbear]

airating is not without a price. It will slightly lower the TA while it raises the pH....which technique you use (borax, soda ash, airating) really depends on how much impact you want it to have on the TA
Soda ash raises both pH and TA fast
Baking soda raises ph slightly and rasies TA fast
Borax raises pH while only slightly raising TA
Airating raises pH while lowering TA, how much it lowers the TA is dependant on what the pH is when you start airating. the lower the pH the more you will lower your TA to get to the same target pH

Hope this isn't too confusing!