I received a beer kit for Christmas and it came with some sanitizer. I don't remember the name but it was a powder. That sanitizer has since run out and I bought some Star San at my local brew shop. I don't know if it is because it is a liquid but I'm having issues with it foaming pretty badly. I added it to both my glass carboy and my large cooler (for sanitizing bottles) before adding the hot water. Is it better fill with water first and then add the sanitizer?