soda ash

[chem geek]

Soda Ash is Sodium Carbonate so using it will not only raise your pH, but will also raise your alkalinity much more than Borax (since Soda Ash contains carbonate -- the same stuff that's in sodium bicarbonate or baking soda that you use to raise alkalinity). If that's what you want, then fine, otherwise use Borax, which does not add carbonate. Another way to raise pH without adding carbonate is to use Caustic Soda, aka Lye or Sodium Hydroxide, but that's a nastier chemcial (in the same sense that Muriatic Acid is nasty to handle).

Though it takes more weight of Borax to raise pH than it does with Soda Ash or Caustic Soda, did you analysis of net cost come out against Borax? That is, for the same pH rise does it cost more to use Borax than Soda Ash or Caustic Soda?

BTW, Janet is correct that 20 Mule Team Washing Soda is the same as soda ash which is sodium carbonate and will raise alkalinity (TA) more than Borax or Caustic Soda (lye) will.

Richard