ALL 11 of my koi died over night.

I had my water tested and everything was perfect. Nobody can understand why all 11 of my koi died, and my catfish and two plecos lived. It makes no sense at all. It was very hard burying all my babies.

Im so sorry to hear that, was there any marks on the bodys at all? Did you see what the gills looked like? What was the weather like on the day and over night? Any powercuts during the night?

My first guess would be oxygen levels if all of the Koi died but hopefully we can get to the bottom of this for you.

this seems to be the same as the pleco thread? I have put exactly the same comment on there ref oxygen supply...

i'd say oxygen deficiancey

the plecs are from warmer tropical climates and as a result have evolved to survive in the lower ocxygenated waters of warm water while koi and other coldwater fish require far more oxygen as they evolved in cold water which holds more oxygen

thats about the only reason they aren't suited to hotter countrys unless you have lots of oxygenation in the pond, if i lived where you live (Florida isn't it?) i'd grab some oscars and put them in as they are found in the florida waterways, but then any south/central american fish would work, but not the uber big ones like the alligator gar

Hm. Sounds about right to me. Thanks again!