Well......I inderestimated how big Jumbo Pekins were. Although my two Brutus twins are only two weeks old, it is painfully obvious that those clowns will not fit in my 75 gallon pond, let alone there two siblings, so time for a bigger pond. I have successfully filtered the 75 gallon pond that currently houses my two khaki's. I am considering building a ~1600 gallon pond in the duck run that is almost finished. My question is how dirty will the water get with 400 gallons per duck? I'm assuming with that much water it will take longer to foul up which will make filtering much easier than the 75 gallon which is only 38 gallons per duck. Larger duck ponds don't seem that dirty. I'm designing the filter system now because I want to bury the pipes and make the new pond really nice unlike the frankenpond I have now.