Michael Garcia apparently used oyster shell to make his vat alkaline. Oyster shell s are 95% calcium Carbonate . When I asked him about this he said it was a joke! He said he wanted to use mineral lime but was told nobody would think it was an organic vat. so he used crushed oyster shell, but he told us to use lime. Gardeners lime rather like Oyster shell is mostly calcium carbonate and will only make the vat mildly alkaline. I have just made up a vat suing it and the vat is pH 7-8. Builders lime on the other hand is what is known as slaked lime or calcium hydroxide and what is used in a zinc lime vat,. Michael Garcai said to use lime as it was very active ( and technical formula h wrote down was calcium hydroxide) and the whole time at the back of my mind was the thought but how can oyster shells do this but the thought stayed at the back and never came to the front of my mind! It is a long time since I did Chemistry!
Lime (apart form being a fruit) can mean:
Calcium Oxide- unslaked lime
Calcium hydroxide -slaked lime.
Fine but where do the oyster shells come in?