Tracking mistakes 2

Today following Zachary Jones and Jeff Edwards advice I checked pH level of rockwool that I used submerged in water. Result was unsatisfactory - about 7.5.

Such environment is too alkaline for spinach. As I mentioned in my last post optimal pH level for spinach is 5.6 - 6.0. It means that if I'll try to germinate spinach on rockwool in future I'll have to add some acid to it.