Gohoenix

So we’ve not had our hot tub long and I changed it a week ago and added some chlorine to keep the water sanitised as I knew we wouldn’t use it for a week. I’ve tested it a week later and the Ph is 6.6 which is too acidic and I’m now panicking that I may have damaged it. I’m currently working on correcting this but does anyone know how long left this way may start to cause corrosion? It’s been a week and when we went to use it tonight the thermostat say 35 degrees but I don’t think it was anywhere near that temp.