sick fish

Question
i have a large gold fish in my 1200 gallon pond and i have one large goldfish that lays on its side on the bottom of the pond but when i get close to it it kinda swims away but ends up going to the bottom again. it has been in my pond for about 3 years now and there is nothing wrong with any of the other fish. im located in ohio i have the waterfall and a spitter running along with a floating heater is it just old or is it sick

Answer
Hi Dave,

Thank you for your question.
I think that the possibility of sickness is relevant.
When fish are "hanging" most often they are injured or having a type of sickness.
Are the watersamples ok?
Then you may want to check the fish closely and maybe take a sample to examine by microscope to make sure there are no parasites on the fish.
When one fish is sick it can be injury or internal sickness.
It's possible that it's the first fish getting sick and spread to others.
Then it can be parasites, viral etc...
Best thing is normally to get a vet involved to check out parasites if the watervalues are ok.

Regards and best of luck!