I am 15 days into a Hodgson Mills Rye flour starter and I have bubbles but only a 50% expansion of the starter.  The ambiant temp is about 66 degrees.

I am using 1:2:2 (starter. flour, water) but it is looking pretty weak.

Do I try

1. 1:3:3 or more...
2. Pineapple juice..a dash
3. A bit of yeast..a dash
4. More patience..a lot

Thanks.