You might want to keep in mind that sodium chlorite is 50 times more toxic than chlorine dioxide. If you don't activate it enough you will have a higher ratio of sodium chlorite.
If you want to get the PPM down you should just dilute it with more water instead. You can use a lower amount of citric acid and get the same activation as lemon or lime because citric acid is a better acivator.
The best thing would be to take lower doses and more of them.