I bought the koi 4 days ago along with another 5. He's about 8cm long. He just sits at the bottom of the pond like hes dead and every now and then he swims around but he thrashes his head about then just drops back to the floor for another few minutes. He's been doing this for 2 days now and all the other koi seem fine. I have 10 koi and 3 water plants.
Thanks
Thanks