Previous to these last two years was the veggie filter thriving? How large
is the pond you are pumping from? Usually you want to do the volume of the
pond per hour. I have a 7'X7'X~2' pond that I was pumping at 1200gal/hr
into the upper pond that is about 2.5'X2.5'X~2.5'... This I was pumping into
a small barrel liner at a very slow rate (with a little filter pump that at
most did 200gal/hr). The faster speed was a little rough on the plants but
they still did well and the upper little barrel liner thrived to the point
of becoming a solid mass of roots. Are you by any chance filtering the
water before you pump it into the veggie filter?

"Happy'Cam'per" wrote in message
...
"lee" wrote in message
...
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.

Drop off the Key Lee, get yourself free
I would say theres to much flow, 500 gallons an hour sounds hefty, any
chance of teeing off your flow so that flow is reduced somwhat?
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**So long, and thanks for all the fish!**