What is your flow rate through the area with the plants? How deep is the
water? Have you had success with them before or is this the first time
you've done it? If your temperatures are a max of 62F (17C) then I would
think it is still too cold to be getting much growth. We have had much
warmer temps than that and my water hyacinth is just now getting a real
start.

"lee" wrote in message
...
Plants in the vegie filter and pond are not growing strongly. Water cress
leaves are very small despite a good root system and plants in the pond
show
little growth. pH is 8.4. GH 60 mg/L KH 120 mg/L.
Pond is 1000 gallons and has 5 koi and 6 goldfish. Day time temp is 17c.
Feeding plants with potash and epsom salts has helped green up the leaves
a
little. Anyone suggest how to get the plants into growth. Many thanks. C.