I put one fog unit in my 29 gal, 16" tall container that I intend to use for my budding res. As I feared, the fog would not rise to the top. It would only rise about an inch or 2 above the surface of the water, even after 90 minutes. Dad gummit. So I put in another fogger. Same thing, with perhaps the level 1/2 inch higher and a slightly denser fog, but barely any noticeable difference. I thought that maybe if they run a long time they will eventually fill up a big container. No such luck. I turned off the foggers to see how long it takes for the fog do dissipate, or disappear, and it was much faster than I expected. In this tub the fog was gone in about 15 seconds. That's why the container will never fill to the top.

The fog made it to the top of an 8 gallon container but it wasn't very dense at the top. Seeing the very small amount of change from doubling the output, I'm certain that the fog won't rise to the top, even with a 3 head unit, and maybe not even with a 6 or 10 head unit.

So I walked a couple feet and noticed how violently the fog swirled around in the container from the slight change in air flow, and good size wisps made it to the top. It was then it struck me that a fan is going to be the key if I don't want to buy a 20-head unit. I put a short hose over the top and gently blew through the other end, and wallah - the tub filled with fog. I also tested if the action from an air stone would circulate the fog enough, but there was barely any change.

So now I'm either going to make a separate pumping machine like the Nutramist ones, or cut a hole in the middle of the lid and have a small computer fan blow straight down. The pumping machine would solve the heat issue, but I'm not real worried about that after testing in a bigger reservoir. The water temp did not fluctuate from 84.5 degrees, even when using 2 units.

So, the light. Should I just put a bit of black silicon tape over the red LED, or not worry about it affecting the roots? Another issue solved with a pumping machine.

The 2nd photo is after 1/2 hr, and the 3rd is using 2 foggers, after the few seconds it took for my camera to turn on after blowing through the tube. The fog was actually a little thicker near the top when I blew.