Starter not thriving
I started my sourdough 10 days ago. Equal parts water and all purpose flour. I had some dry instant yeast from 12 years ago and added about a teaspoon full. I figured the Yeast wouldn't grow because I had put some in sugar water and there was barely any activity. The 1st 2 days the jar filled up nice and bubbly with lots of bubbles all the way through the jar and after 5 days I made some bread and it came out pretty good. I continued to feed it with whole wheat flour and water I started out at twice A-day feeding once in the morning once in late afternoon but now 10 days later I've cut back the feeding to once A-day and I get nice aroma with some bubbles on the top but nothing like I did the 1st 2 days. I do a float test and some of it floats some of it falls to the bottom of the bowl so I don't think it's very active. I see photos of starter that have bubbles all the way through the starter but mine never looks like that, it just looks like a jar of water and flour. Any suggestions? I'm not opposed to starting over if need be.