You have not wasted the borax. Many people add borax to 50 ppm because of it's agaestatic and pH stabilizing properties. If your TA is 0 PPM you need to RETURN THE ALKALINITY INCREASER TO THE POOL STORE and but the same amount of baking soda and add that. Here is a hint Total alkalinity increaser is baking soda. Read the package, It will say either sodium bicarbonate or sodium hydrogen carbonate, both are just other names for ordinary baking soda!