Watercress loves moving water, the faster the better. The roots do a
great job filtering and if you get too much you can have some for
lunch.

--
some photos of my little puddle
http://community.webshots.com/user/hankpage1

"Elaine T" wrote in message
om...
I'm finding that the water in the lower two barrels of my pond is
too turbulent for small floating plants. The water lettuce seems to
ride its way to a quiet spot against a marginal and stay, but the
azolla gets pushed under at the spillway outflow and tumbled around
underwater. Then its roots fall off and clog up the filters. I've
finally netted most of it out of the lower barrels, except for some
that's more or less "corraled" with black airline tubing because the
fish need the shade. Not exactly elegant.

Even worse, I learned that azolla fixes nitrogen. I now suspect
that the nitrogen fueling my green water is from decaying bits of
azolla roots everywhere - I had a nitrate source and didn't even
know it.

I wanted lilies but don't know to tell whether conditions are OK for
them in the lower two barrels. Flow is about 200gph through the
spillways connecting the three half barrels, with the spillways
ending about 2" above the water surface for light but not excessive
splash. From watching azolla and submerged plants, the current tends
to flow down from the spillways, up on the far side of the barrel,
and splits to flow back towards the spillway around the sides. I
tried to set the ball valve at the lowest setting where all the
debris (currently Cambomba leaves and azolla roots) ends up in the
bottom barrel with the filter. The top barrel is different because
it has the pump outflow at the bottom so the surface is less
disturbed.

Can anyone take a guess about lilies or suggest other large floating
plants that are tolerant of this sort of current to shade the pond?
And legal in California - I can't find water hyacinth and only got
water lettuce through a friend. Or do I have too much current?

Thanks so much...again!

--
__ Elaine T __
__' http://eethomp.com/fish.html '__
rec.aquaria.* FAQ http://faq.thekrib.com