Last summer I went out in the boat on the pond at night with one of the under water fish viewing cameras. I let the boat drift across the pond as there was an ever so gentle breeze.

The camera has infra red lighting for night use. I would run across the occasional fish, but one thing I noticed on the screen quite often was some type of what I assumed was a tiny bug. It was above microscopic, because it showed up as movement on the screen. Yet it was so tiny it must not have been more than a few pixels on the screen. It moved with jerky movement across the screen. These seemed to be thick in the upper few feet of water in the heat of the summer at night. Water temperature likely in mid 80's.

I was amazed at the life in the water. It was more like a soup than just water. I've also noticed this in the ocean diving. What appears to be very clear water in the day time, during a night dive with lights on, the water resembles more a thin soup of life rather than just water.

Would these tiny critters flitting across the screen likely have been Daphnia? What other small critters could it have been?

Daphnia

Very likely Daphnia or another zooplankter or groups of several species. They have a diurnal (daily) migration moving toward the surface at night and downward during the day or bright light.
http://www.merriam-webster.com/dictionary/diurnal

I see the same on my ponds. And as the winter progresses the numbers seem to explode. The IR light shows whole new world. I love the soup reference, perfect comparison. Wait until Bill Cody chimes in here...this is his wheel house!!

Too funny...Bill..you beat me to it

Wow! In winter they explode! I would not have guessed that.

I probably should have been a little more precise..Not sure if there numbers are up or more movement is being observed. We just notice, under the IR light of our underwater cameras, more of what we call "the bouncing balls". I have no idea what's going on but I would wager a pretty hefty sum...Bill does!!

Do Daphnia naturally occur in new ponds or do you need to do something or stock them to get them started?

Daphnia graze on phytoplankton, among other things, and occur naturally, just like phytoplankton.