I recently had to put a few small koi (~4 inches) in a plastic container for treatment against -probably- sleeping sickness. In this container I added some stuff, like a PVC pipe so they could hide and be protected from the torrent of the airstone, some activated carbon and I even tossed in a few plants: some watercrest, some duck weed and a floating mosaic plant.
I wasnt overly cafeful and a fair amount (say a tea or table spoon) of soil ended up in the tank, that was attached to the plant roots, dirt in the bucket I used or whatever. It sank to the bottom, and soon after I noticed the koi "vacuuming" the bottom of the container. Sucking up the dirt, and I assumed, spit out anything inedible. Except the latter I never saw.
2 days later.. pretty much all that soil.. is GONE. Its like my maid vacuumed the container secretly! I know koi love to dig in dirt, searching for food, but do they actually eat it? And even if they do, how could they possibly break it down, it would just have to come out again?
I wasnt overly cafeful and a fair amount (say a tea or table spoon) of soil ended up in the tank, that was attached to the plant roots, dirt in the bucket I used or whatever. It sank to the bottom, and soon after I noticed the koi "vacuuming" the bottom of the container. Sucking up the dirt, and I assumed, spit out anything inedible. Except the latter I never saw.
2 days later.. pretty much all that soil.. is GONE. Its like my maid vacuumed the container secretly! I know koi love to dig in dirt, searching for food, but do they actually eat it? And even if they do, how could they possibly break it down, it would just have to come out again?