1st try: Leader's Stiff Dough Starter/Levain

Hi all,

I'm just starting out and I'm at the end of day 4 of trying to create a stiff dough levain from Leader's "Local Breads" book.  Leader describes a long list of properties that a good levain will have when it is ready and mine seems to exhibit a few, but not all.  Most importantly, I'm not convinced that it is growing but a sufficient volume after feeding.  My kitchen was a tad cool at the beginning (67F) but is now 72F.  Each day I'm adding 30 g of water, 50 g of all purpose organic and 5 g of organic (hard) whole wheat.  I'm getting the smell, there appear to be bubbles forming and the dough is certainly tasting tangy but it just isn't rising as much as I expect.  I have it in a metal mixing bowl so I am not actually measuring its volume, but I'm sure it isn't doubling in 24 hrs.  It certainly isn't crawling up the sides of the bowl.  Leader describes the formation of 'visible gluten strands' but I don't know what these look like.  Can anyone post photos showing the progression of their stiff levain?  Beyond following the daily routine, is there anything else I can try?