u/Alternative_Donut406

We've inherited an awesome fish pond with our new house, we've had to spend a week cleaning it and fixing cracks but now it's full, some newer plants in that aren't trying to take over, and the fish seem really happy. We have 2 or so fish out of the 40 odd with a couple bumps, could these be tumours?

I know we've got more work to do on the pond but at least now they have room to swim, I just want to make sure there's no disease being spread which would be more important than pimping out their pond.