Ewest really to me the 1/2 acre pond is hard to explain with just a trophis sclae (the others fall between either Eutrophic to hypereutrophic). The reason why is the pond itself is just a mud hole (aka turbidity) (never even seen a plankton bloom in the pond itself) with a great water source. The pond turns its water ruffly every 3 days (I have only mesured the water leaving the pond spillway and it regularly measured around 300 GPM over the years (the other 2 ponds supplied with natural less rich water exceed that). Like I say the pond is close to 4 acre water ft. and exit water volune is near 1.33 acre feet per day. I draw water from both top and bottom as I also siphon for irrigation during the growing season (may thru oct). The water comes in well areated (due to the elevation changes with alot of water falls anywhere from inches to right at 6' at the last drop). The water is in great shape as there is plankton pools / ponds upstream that feed into this water and into the pond. To me Trophic scale has more of a representaion for a static water level pond or lake with not so much volume change like a river or creek. I would actually put this pond on the low end of the trophic scale for a pond and high end carrying capacity. this is due to kind of like caged fish in larger water enviroment with the inflow of good water and the transfer water volume. The only limiting factor I have found for the 1/2 carrying capacity has been disease. Catfish is also the only fish that do well in the 1/2 acre. If you think about it like I do, I basically have the annual water volume of a 60 acre 8' deep static pond with around 2,500# of fish in it (currently) and that is no great accomplishment. That is the explanation I have given people to the years to why I have a lifeless (low trophic scale) looking mud hole filled with alot of fish doing well.
