United Kingdom 
we have recently rebuilt our garden pond which is approx. 2.5m x 3. x depth 0.6m. About 1/3 of the original water was returned to the pond along with the fish and oxygenating weed. This weed was floating free on the surface but has now mysteriously sunk. Does this matter?
14 May, 2010
all of my oxygenating weed lives on the bottom, are you happy with it on the bottom?, if not possibly try a water lily to give surface cover.
14 May, 2010