Milk fed sourdough
I have a sourdough starter I got from a friend out west who said she had been feeding it a 50/50 mix (by volume) of AP flour and skim milk. I have been using it for over a Month and it has been performing so far. However I have started to notice that the activity level seems to be decreasing and actually it has only occasionally doubled after feedings. Only recently did I read the advice of sourdolady and others on this site to toss most of the starter and feed at least 1:1:1 or greater ratios. I have been keeping a 4 cup measure half full or more and using the starter for bread, pancakes and waffles. From the sound of it I have been starving the starter by not doubling the batch.
Now, what I would like to do is switch to water instead of skim milk. We have well water and although I don't have a PH meter I think I recall that generally the water in the Midwest US is a high PH around 9. The other thing is that we live in an area that people have to replace the zinc rods in the water heater every now and then. If you don't change the zinc rod we get a nasty smelling bacterial from the hot water tap. So, I've been using only cold water for any bread mixes just to eliminate the possibility of picking up an unwanted bacteria from the hot water. This hot water deal is a wide spread issue according to my plumber that affects most of the country.
The questions then are: Can I just switch over to water from milk or is there a transition procedure? I really like this starter and the full body aroma it gives off and I understand it is quite old so I don't want to kill it. I find it difficult to keep fresh skim in the fridge all the time since we don't drink that product. And, have I been starving my beasties?