Thanks for the replies so far.

It sounds like I can get either the small river rock pebbles or the pea
gravel from the construction section. Which one is better? Is the
pebble smooth surface preferred or gravel rough surface? Anything
related to beneficial bateria here?

Still debating about the sunken pots vs lining the bottom of the barrel
with soil, how thick a layer of soil do I need? Can I use regular
nursery pots instead of the aquatic pots (more holes). It might be
easier to plant with the bottom soil layed out than having about a
gallon pot for each plant, right?

I am thinking of using a regular nursery pot up side down and cutting a
door out for the fish to hide in the shade and also use as a "plant
shelf".

I have trouble locating a dwarf water lily. Can I get a regular water
lily? Where do I look for these because aquarium stores don't sell
floating plants.

I have read about they don't like ripples, the pump valve adjustable
and I am running it for aeration, I could make it very gentle if
needed.

I am in Northern California do you think I can run it during the winter
here? It might get to 32F at the coldest point of the year, but with
the fountain pump I don't think it would freeze.

Thanks again