When I do a population suvery on the lakes that holds goldfish populations I found very few large goldfish that is over 10" but 5-6" goldfish are very dirty common. But Johnnylightning is right, if there are predators are present, all of your 50 goldfish will be gone very quickly. It takes a fluke for a goldfish that escaped from the predation to grew into a large one.
Exactly I use to have a small less than 1/2 acre pond behind my house with only sunfish and mosquito fish. We put five koi and about 100 goldfish all over 2 inches. It was about 5 feet deep. Before we move we drained the pond after 3 years later since the new owner didn't want the pond we found 4 koi and no goldfish. We only saw two dead in those three years but after 1st year we never saw any. The reason we concluded was the goldfish swam towards the top a lot making them easy prey for birds. KOI usually stayed hidden because we really thought they were dead also until less than a foot of water was left. We found an abundance of mosquito and sunfish that we transfered to another pond across from us. We gave the KOI away.
Sent from my PG86100 using MonsterAquariaNetwork App
