Hi all, noob here with a question about chlorine. I have been reading heaps of articles from this site which has helped immensely and have decided to follow Nitro's Dichlor/bleach method but am having issues with products. I have the water balanced fairly well and CYA is at about 30 ppm. I purchased some unfragranced White King brand bleach from the supermarket and added it a couple of times but I had foaming issues. I since found out White King has added soaps in the bleach that are not listed on the ingredients so that was a big fail. I went to Bunnings (big box hardware warehouse in Aus) and bought 2Kg of granular Pool Chlorine which has 650g/Kg available Chlorine present as Calcium Hypochlorite. The label on the back says "Do not use this product in spa pool water". Is this a load of bollocks or is there another additive in granular pool chlorine that can cause issues in spas and hot tubs?