When to deflask is really more of a preference. Ideally, one would want to grow them as large as possible in the flask and take them out when they are at their peak growth. If you wait to long they run out of food and growth slows. As long as they are green, healthy, and growing well I'd leave them. As soon as they look like they've run out of space or nutrients it's time to deflask or replate.
It's hard to tell in those small pics, but it looks nice and full. Ruben grows them nicely, huh?