Thanks for your replies. The filter gets full sun and the flow rate is 500
gallons an hour. The filter is 12 inches deep and this is the second season
of poor growth.
"nswong" wrote in message
...
Hi,

"lee" wrote:

Water cress
leaves are very small despite a good root system and plants in the
pond show
little growth. pH is 8.4.

Feeding plants with potash and epsom salts has helped green up the
leaves a
little.

Floating plant with very long root are nutrient deficiency symptoms.

Small and yellow leaves are nitrogen deficiency symptoms.

Nitrogen will start to reduce availability when PH are higher than
8.0.

Fill a tub with your pod water, put in a few Water cress, lower the PH
to between 6.5 and 7.5, wait a few days and see what is the result.

Or add some nitrogen into the tub water.

This is from what I read, not personal experience, please post the
result here if you can, I will like to know it.

Thanks,
Wong

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Latitude: 06.10N Longitude: 102.17E Altitude: 5m