October 1, PH 9.5, vat temp 13.7, color test blue
October 10
October 15, PH9.2, vat temp 13, color test blue
October 24, PH 9.3, temp 12, color test light blue. Vat 2 is completely stopped. only vat1 is active.
I was not hopeful that we can dye in October. The outside temperature is definitely below 20 (between 10-18) and some nights has been already around 1-2 degrees. But with a nice surprise, our vat still functions even when the room temperature is 14 and the vat temperature is below 12!
I was surprised to see the blue hana bubble on the vat after mixing it. I know the PH is dropping now to below 10, but as I do not want to make extra stress for the bacteria, I am not raising it for a while and see how long it can sustain this situation. On October 15th, I started to add 15g of calk to raise it a bit, but not very drastically.