I've posted before how discouraging it has been that I stocked too many triploid grass carp (180 in a 6 acre pond). The first 10 years or so the water looked pretty good. There fewer and fewer weeds and algae each year, and the water was relatively clear. Now, 20 years later, the water becomes greenish-brown when late summer arrives. A secchi disk disappears totally at 22". The GC have eaten every bit of rooted vegetation leaving only an overabundance of phytoplankton to take up the nutrients and turning the water cloudy. Much to my dismay, the grass carp don't ever seem to die.
I've recently read where the ideal number of GC is almost impossible to achieve. Either they are under stocked and the weeds aren't controlled, or they are overstocked and green water is the result.
I would be very interested if anyone has seen just the right balance after GC were in a pond for more than 10 years. A perfect balance for me would be moderate weeds and algae and nice clear water. Are there any success stories out there?
