We are using Baquacil in our pool and are trying to eliminate a multitude of iron stains from the bottom of our vinyl liner w/o too much expense. Have been reading online articles about using Vit C to remove these stains after lowering the pH to 6.8. Question - does ascorbic acid compete with peroxide? Do we have to lower the amt. of Baquacil Shock and Sanitizer? Also, can we use products such as baking soda, muriatic acid, and borax to adjust pH/alkalinity?