Single-Tail Goldfish (Pond Type)
Common goldfish, Comet, Shubunkin. Streamlined body. Strong swimmers, eventually 12-18 inches.
Need pond setup — 200+ gallons minimum, ideally 1000+ gallon outdoor pond.
Fancy Goldfish (Aquarium Type)
Oranda, Ranchu, Telescope, Black Moor, Lionhead, Ryukin.
Round body, slow swimmers, sensitive to swim bladder issues from selective breeding.
Aquarium dwellers — 75+ gallons for 1-2 fancies, 30+ gallons per additional.
Why Don't Mix
Single-tails outcompete fancies for food, swim faster, push fancies aside.
Single-tails are happier in ponds. Fancies are happier in aquariums.
Choosing Right
Outdoor pond — common, comet, shubunkin, koi.
Indoor aquarium — fancy varieties only.
- ✦Quality matters more than rarity for goldfish health
- ✦Fancy goldfish under 6 months old are still developing — pick mature stock
- ✦Watch for swim bladder issues immediately, fix with peas if visible