Soaking... why?

[Lolo76]

My JCP Kipling is about 3 1/2 years old, and until now hasn't been much of a soaker... he's always seemed content with the humidity levels, and I've never had to mist him or anything. But for the last month or so, he's been soaking in his dish almost every day!! I checked thoroughly for mites, and see no signs of them - not to mention, the other 20+ snakes in the room have no mites, and are not soaking in their water (he's the only Morelia, though). He appears otherwise perfectly healthy, and his last shed was one piece IIRC. I have two possible explanations for this behavior, and hoped to get some opinions/advice:

1. I recently upgraded him from a 28qt to 41qt tub, and was using the same bowl at first. I've since switched to a larger one, and even added a second this week, but he's still hanging out in the water. Maybe I need to start misting with this larger tub?

2. We moved from chilly/foggy San Francisco to warm/dry San Jose last year, and ambient temps here never get much above 30%. But this is now our second summer here, and I don't recall him soaking last summer. Maybe he's still adjusting to the weather, and/or it's just hotter this year?

Got some cute pics, though - LOL! This first one is with the old bowl, and the second shows the larger one (of two) he now has in the tub... his scales do look dry in these shots, but they don't look as dry in real life (might be the flash).