I have a 2,200 gallon koi pond that houses 16 fish, 2 turtles and two lilly plants.

The original 1/2 hp pump failed after only 1 year and the installer came out to replace it and in doing so replaced it with a 1hp pump (2x the original size).

Seemed like that would be okay, just circulating the water twice as fast? But, the fish have been acting strange since the replacement (not eating, clumping into a big group).

Can anyone tell me if the increase in size of pump is dangerous to the fish or if it is just causing for a differing environment they are just getting used to?

Your input and comments are appreciated.

thank you,