Hi, am on day 3, which I planned first 12 hour feeds. I fed at 7:30. Its filled a half full mason jar, so I dumped a third and it filled it again. Smells like I had real yeast in there, its like a sponge, none of the mentioned bubbles, day 3 can it possibly be ready so soon? Its only 2 pm, second feed should be 5 hours away. I read numerous post but see none complaining the starter is too active.
You can often see a surge of activity on day 3. I would keep going as per your planned schedule. You need more days to get some stability so that you can see a predictable rise and fall of your starter.
This is very typical to see tons of action early on. You're about to enter the "oh no, my starter is dead" phase. :D
Don't worry! Keep feeding it and it'll get there