Quote Originally Posted by Zephyrr View Post
so when the koi get too big my parents have decided to take them to the pond at my grand parents that doesn't have any fish in it, it's an actual pond though, not one that uses a liner or solid plastic or whatever, so I'm worried, will they be harmed out there?

edit: I've also told them that they're supposed to get bigger and they keep insisting that they will grow to the size of the pond
chances are in an unprotected pond, they will get eaten by a predator (heron, otter, raccoon). Sorry to say it, but your parents are mistaken. They are not limited by the size of the pond. A 50 gallon is suitable for maybe 2 goldfish and even then, only with good filtration.