In CSM stock solution add about 2g ascorbic acid + the 0.8g of potassium sorbate/2000mL. If you look around HCL (about 10mL of pool acid) and 40-60mL excel is also used to prevent mold. Smaller batches of stock solution might also be an option. When mixing add the CSM+B last.
Tom Barr;45807 said:
Add HCL first to the water. Wait a few minutes and mix, then add the dry trace mix to that mixture.