“Like sardines in a can” isn’t a description pond owners want for their ponds because of the drawbacks.
Too many fish per gallon can overload the pond with ammonia and make your fish sick. Crowding fish can make them uncomfortable because they won’t have any room to grow or swim! It would be like getting into a crowded elevator and needing to stretch your legs.
They also may breed and cause the pond to become overfull. When deciding on the amount of fish your pond can hold, keep these factors in mind:
A pond with mechanical and biological filtration and aquatic plants will better sustain fish than ponds without them. If you want more fish you can add filtration and aeration so the pond can support them.
As for actually introducing new fish to your pond, you’ll want to follow proper fish introduction procedure.
Now let’s get into the rules of adding fish to a pond!