how deep does a goldfish pond have to be
The rule of thumb is smaller ponds that are around two feet deep are perfect for Goldfish, but Koi need to be kept in deeper water and much larger ponds. However, the deeper a pond the better no matter what size it is.f it's a smallish pond, then Goldfish would be the better choice because Koi need a lot more space. In fact they should not be put in ponds that hold less than 1000 gallons of water and depth wise they need a minimum of three feet or preferably more in order to do well and thrive.