Alkalinity vs. PH

[Laurie]

If Alk and PH are low, which do you increase first?

[chem geek]

Generally, you adjust the Total Alkalinity (TA) first since it will tend to make the pH rise, but it really depends on what kind of pH Up product you plan to use and how low your pH is. Most pH Up products are sodium carbonate which will raise the pH and the TA. I have a spreadsheet that calculates exactly what would be needed. If you post your starting pH and TA and your water volume, I can tell you what you need.

Richard