Here are some helpful facts about Soda Ash injection: 1. 0.926 lbs. of soda ash mixed with one gallon of water makes a solution of 10% Soda Ash. 2. A 10% soda ash solution is 100,000 parts per million soda ash. 3. It is common to inject between 50 and 500 ppm soda ash to increase the pH of well water.