Very large bubbles in starter
So I have been trying to cultivate some sourdough starter (1:1 flour water ratio) and feeding it twice a day. I always get large bubbles (as opposed to lots of tiny foamy ones) in it that pop when some is scooped out and thus I cannot do the check of it floating in water to see if it is ready to use. Is it OK that my starter is like this? Do I need to use more water? Why are the bubbles so big and easy to deflate?