In article k.net, "Snooze"
writes:

The roses that seem to be the happiest are the ones that get a bulk of the
muck that builds up at the bottom of my ponds filter. I just attach the
garden hose to the drain, and open the valve. Water & fertilize in 1 easy
lazy step.

When I only had a few plants in pots I used water from the canal. I could see
a big difference when I used this water instead of tap water. I still use in
on newly potted plants, seems to give them an extra boost. There must be extra
nutrients in this type of water, whether from the fish or fertilzer runoff from
everyones lawn.