Adding a Second Koi to a 2,000+ Gallon Pond with Goldfish

Owner has a 13-inch scaleless (Doitsu) black koi with silver markings in a 2,000+ gal pond with goldfish, lilies, lotus. Koi hides under plants. Asks about variety ID and adding another koi.

Koi Variety

Scaleless koi = Doitsu (German carp lineage). "Black with silver" suggests Karasu (black) with Ginrin (sparkling scales) or Kumonryu (pattern-changing). Exact ID needs photo.

Adding a Companion

• Koi are social—one more is fine.
• 2,000 gal supports 2–3 adult koi max.
• Quarantine new koi 4+ weeks.
• Match size to reduce bullying.

Hiding Behavior

New koi often hide for weeks. Provide shelters (PVC pipes, caves). Ensure it's eating—offer sinking pellets near its spot.

Enjoy your growing collection!