If you push the fertilizer tab or stick a few inches into the soil it will
not
leach back out. People often place pebbles on top of the soil to keep
the koi and goldfish from digging in the dirt. That messes up the water.
Some are using gravel instead of soil for their plants that they do not
fertilize. The idea is the plants take all their nutrition from the water
so
why bother with the messy soil.

I have over a 100 plant containers in the ponds and it seems that one
always gets tipped over or dug into. It makes a mess. Was looking into
non soil media a while back and the only affordable thing I found was
gravel (rounded not sharp). But it may not work for lillies in that the
gravel would allow fertilizer to leach back into the water.

Howard

"YSL" wrote in message
...
I get it that people using closed bottom pots for lilies, but how to seal
the top then? Is there any way? Like place pebbles on top? They won't stop
fertiliser leaking back to water. Thanks a lot.

YSL