Help with my starter
I'm new here and new to sourdough. I've been reading a lot of advice here. I tried a starter from flour and water, and while there was a very small amount of bubbling and now nasty smells - it never really got going. Only a few tiny bubbles every appeared on its surface and while it didn't smell bad, it never really got going at all.
I then tried a grape based starter, which was wonderful. After 4 days, the grapes were very lively with bubbles, I added flour and it was foamy and wonderful. I then added more flour and water until the total weight was around 500g - and this rose to a very lively and foamy peak after about 5 hours. But then, I took half the mixture away and added in flour (100g) and water (150g) to make it back up to 500g - and suddenly there was very little response. No bubbling, no foaming and what looked like a thick layer of hooch developed with a scum of flour on top of it.
I have been using tap water, which in the UK where I live is hard water. Is this possibly the cause? I've just added some vinegar to the starter, while doubling it, and will see if that has any effect... but I'm wondering whether I'll have to use bottled water after all, for my starters in future.
Thanks in advance for your help.