I want to stock my earth mud bottom pond with Koi. It's on average 4 feet deep, and about 30' x 70'. Im wondering if they will muck up the bottom and just stay there, or will they swim around like they would in a rock bottom pond. Maybe goldfish are a better choice? Any suggestions out there? anyone... anyone... bueller?

Koi are aquatic rototillers and feed like pigs continually rooting in the pond bottom for food items. Koi in rock bottom ponds also root in the bottom sediments. Except in rock bottom koi ponds the ponds are mechanicaly filtered and not a lot of organic sediment is present on the bottom for resuspension into the water column. Plus, liner koi ponds have constant mechanical filtration to continually remove suspended sediments produced by rooting koi. Koi root, that is what they are instinctively good at. If you think koi do not root in rock bottom ponds then you have not watched or observed them for long periods of time at all hours of the day. Koi in koi ponds usually know when people are nearby so they cruze in open water waiting for fish food handouts. When they think no one is around for food handouts, they often get back to looking for food elsewhere.

Expect cloudy water with koi in the earth bottom pond. Water claity will be proportional to number of koi. My rule of thumb is one or two koi per 0.1 acre will not make the water overly cloudy (visibility 2.5-3 ft). Pond aeration with koi will almost always make cloudiness worse. Reproducing koi in a pond without complete elimination of offspring will lead to very muddy waters.

Goldfish in high numbers will also make a pond cloudy. However it takes more goldfish per acre than koi to create the same degree of turbidity. Goldfish numbers also need to be controlled so they do not overpopulate.

Thanks for the info! That's a shame. Whats the point in having KOI if I cant see them. That saved me some bucks. I'll have to stick with my trout.