ZNA Singapore Koi Show Entry Guide: Class Bench and Judging
The annual ZNA Singapore koi show is the only formally-sanctioned international koi competition held in Southeast Asia, and entry into the bench tanks is the credentialing event for serious local koi keepers. The ZNA Singapore koi show follows the protocols of Zen Nippon Airinkai, the parent Japanese organisation that has codified koi judging since 1968. This guide from Gensou Aquascaping at 5 Everton Park covers size classes, variety benches, judging criteria, and the registration logistics for Singapore entrants.
What ZNA Is and the Singapore Branch
Zen Nippon Airinkai (literally “All Japan Beautiful Koi Society”) is the older of the two main Japanese koi judging bodies (the other being Shinkokai). ZNA Singapore was established in the late 1990s and runs an annual show typically held in May or June, often coinciding with the Singapore Garden Festival or hosted at venues like Riverlink. The show draws entries from Singapore, Malaysia, Indonesia, and occasionally Hong Kong and Taiwan.
Size Class Structure
ZNA size classes follow Japanese convention measured by total body length: Yochigoi 15-25cm (juvenile), Wakagoi 25-35cm (young adult), Tategoi 35-45cm (developing showpiece), Kanjyu 45cm and above (mature show grade). Larger fish typically score higher because koi quality is most evident at size, but skilled juvenile bench entries (Yochigoi) can win Best in Class against weaker mature entries. Equipment from aquarium equipment like quarantine tubs and bagging gear supports the show transport phase.
Variety Benches
Koi are also benched by variety: Kohaku (white with red markings), Sanke (white with red and black), Showa (black base with red and white), Utsuri (black with one other colour), Bekko (white/red/yellow with black markings), Asagi (blue net pattern), Shusui (doitsu version of Asagi), Tancho (single round red spot on head), Ginrin (silver-scaled varieties of any base), and the Hikarimuji (single-colour metallic) and Hikarimoyo (multi-colour metallic) classes. Each variety bench awards Best in Class within each size category.
Judging Criteria
ZNA judging covers body shape (taikei), skin quality (hada), pattern (moyou), colour intensity and depth (iro), and overall elegance (hin). Body shape carries the heaviest weight — a koi with poor body conformation cannot place high regardless of pattern. Symmetric pattern placement, sharp pattern edges (kiwa), and balanced front-back distribution all matter. Skin quality refers to the mucus-coated lustrous surface that signals health and proper husbandry. Treatment supplies from water care and treatment like dechlorinators and biological starters support skin and water quality in the conditioning weeks before show.
Registration and Entry Fees
Registration opens roughly two months before the show through the ZNA Singapore website or Telegram group. Entry fees typically run SGD 30-80 per koi depending on size class. Each entrant is limited to a maximum number of entries (often 4-6 fish across categories). Show committee provides bench tanks (typically 1500-litre vinyl tubs), aeration, and basic filtration; entrants supply their own catch nets and optional padded bowls for handling. Tools from aquascaping tools like soft koi nets and plastic bowls travel with entrants on show day.
Pre-Show Conditioning
Serious entrants begin show conditioning eight to twelve weeks before the date. Diet shifts to high-protein colour-enhancing pellets (typically Saki-Hikari, Ultra Balance or similar Japanese-imported diets). Water changes increase to maintain pristine skin quality. Temperature held stable at 22-26°C. Avoid antibiotic treatments in the final four weeks because residual medication affects mucus production and judges can detect treated skin. Two weeks before show, the koi enters a holding tank with maximum water clarity.
Show Day Logistics
Show day starts early — entrants arrive at the venue at 6am to bench their koi before judging begins at 8am. Transport in oxygenated 60-80 litre poly bags inside insulated containers with cold packs to maintain stable temperature on the journey from home to venue. Multiple trips may be needed if multiple koi are entered. The bench tank assignment is determined by show stewards on arrival.
Judging Day Format
Judging proceeds bench-by-bench through the morning. Judges (often visiting from Japan or senior ZNA Singapore committee) examine each koi from above and through the side glass, score independently, then confer for final placements. Best in Class certificates and rosettes awarded by mid-afternoon, with Grand Champion (best overall fish across all benches) announced at the closing ceremony in the late afternoon.
Post-Show Recovery and Networking
Koi handle bench-tank stress poorly — return them to their home pond promptly after benching ends, drip-acclimatise to home water (the venue water often differs in pH and temperature), and observe carefully for the following week for any stress-related infections. The networking value of attending a ZNA show often exceeds the placement value — Singapore koi keepers are a small, tight community, and a single show attendance establishes you within it. Suppliers, breeders and importers all attend, and post-show pond visits are commonly arranged for keen new entrants.
Building Toward Show Quality
Show-quality koi require show-quality ponds — minimum 5,000-litre filtered ponds with consistent temperature, biological maturity, and dietary discipline over years not weeks. The realistic Singapore path is Yochigoi class entries first, learning the bench-day mechanics, then progressively building toward larger size classes as your koi mature in your pond over three to seven years. Patience is the operative word in koi competition — there are no shortcuts to a 50cm Kanjyu Sanke.
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