Reviving Carl's 1847 Starter..

Ok.. So I'm on my last possible revival -- the 2nd half of my free Carl's starter -- the first was thrown away after a few weeks when I neglected it for several days when my wife was in for hip replacement surgery.. Anyway, I used the 2nd half of the dried starter to start a new batch a couple of days ago..  I mixed the initial amount in a small plastic lidded container that is about the size of a small baby food jar.. 

It wasn't really doing much (no doubling) after the first 12+ hours but I trudged on following their supplied revival instructions and added 1/4C of purified water + flour.  At this point I obviously moved it to a larger container (a Cambro 2qt container) -- the small container used for the initial start had a little remaining left-over starter in it on the sides, so I mixed some more water and flour in there and re-closed the lid to see if there was enough good stuff to have a 2nd round going simultaneously.

So, this morning I find the lid on the small baby-food sized container was popped off and on the shelf below.. I put it back on and put it back in the cupboard -- I checked the larger Cambro container and nothing nearly as interesting going on there -- a few bubbles but nothing else notable -- no doubling,etc.  So, I drop my kids off at lunch time and check the cupboard only to find the small container lid popped off again.. Go figure!  

So... This evening I added a little more water/flour (50/50 mix of Bob's Redmill Rye, KAF Breadflour) to the small mix to create a nice thick paste -- a bit thinner than tomato paste... Similar to what it was last night.. In the big Cambro container, I added 1/4C of purified water + 1/4C of flour mix (50/50 same as above).. This mix is a little thinner in consistency -- more like pancake batter -- but just slightly thicker... After talking things over with my sister-in-law (a chemist), I moved the mix out of the Cambro and into a smaller container (a Ziplock snap-n-seal container that we got when we bought some lunch meats -- all cleaned with warm soapy water and dried before use -- inside & out).  So, I put the lid on, burped it (like a tupperware) and sat it on the island counter... That was around 8:30PM PST.. 

Fast-forward a bit.. I just checked the larger starter in the Ziplock container and it's doubled in size in ~3 hours.. This is a FIRST!!!  I'm wondering if it will be spilled over the sides by morning if it keeps this up...

So... Here's my question for today.. why would this SAME starter decide to start being very aggressive now that its out of the Cambro container and is apparently very happy in the Ziplock container??  Is the smaller amount of surface area in the new smaller container important (less available oxygen -- the cambro had tons of air but the starter was only about <1/2" deep)?  Is the looser fitting lid on the Ziplock better than the Cambro's tighter sealed lid?  Any other ideas on why the sudden change in behavior? 

If this agressive growth continues, is it safe to assume I can use the starter tomorrow possibly?  Since this is a revived starter I'll assume if its capable of doubling in <12 hours it's good for use.. correct?  Many thanks in advance!!!