You can use anyhting yu want to plany in. It sounds like there was a
lont of air entrainment inthe sand yu used, and it eventually all
migrated to the highest side, and in the process floated the
container on that side enugh to cause it to tip over...Just ensure
your sand and soil is thouroughly wet. Rocks would only have given
less grain structure to trap air. I do not know what is in the light
weight potting mmixture, but some of the bagged mixes cntaian perlite
which is very bouyant. SOme containers are also a nitrogen filled
plastic material that is neutral or slightly positive bouyancy, so
that may have added to your problems as well..... Poke some holes in
the containers, and just for an experiment, toss a hadfull of the
"lightweight" soil in a bucket of water and see how much of it floats
or if it separates into small tiny grey to while looking speres..which
would be perlite....

On Tue, 12 Jun 2007 17:14:34 GMT, "Harriett Wright"
wrote:

I potted several small Trudy Slocum water lilies in a container 7 inches
deep and 24 inches in diameter. I used a light weight potting mixture from
Lowe's and put a layer of sand on top. About a week later I looked at my
pond and the whole container was floating upside down! Not quite all the
soil and lilies had fallen out yet but most of it did when I turned the
container over and pulled it out of the pond. What a mess! I had potted my
other lilies the same way, but in 7" by 18" containers, and they seem to be
OK. I always pot my lilies this way, but this is the first time I've used
such a large container.

I called the local pond supply and they told me I should have put rocks on
top instead of sand. Would this have made a difference? I don't like to
use rocks because it makes it so difficult to insert fertilizer tabs.

Unlike the 18" containers, the 24" container was actually sold as a small
pond, not as a plant container. Can I use it? What can I do to prevent a
repeat of this disaster?

Thank you for any suggestions and/or words of wisdom.

Harriett





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I forgot more about ponds and koi than I'll ever know!