About Comet Goldfish
The Comet Goldfish is an American-bred variety developed in the 1880s, distinguished by its long, flowing tail that resembles a comet's trail. They are nearly as hardy as Common Goldfish but more ornamental with their elegant tail fins. Comets are fast, active swimmers that need plenty of space and are unsuitable for small tanks or bowls. Their slender, streamlined body allows them to swim quickly, making them incompatible with slower fancy goldfish varieties. Comets are excellent beginner fish if provided with adequate space and filtration. They come in various colors including red, orange, yellow, white, and the popular Sarasa (red and white) pattern.
Care Guide
Care Requirements
Tank Setup
Comet Goldfish need spacious tanks with room to swim:
- Minimum 30 gallons for one juvenile (55+ for adults)
- Add 10 gallons per additional fish
- Long tanks better than tall - they need swimming length
- Large canister filter (they are messy fish)
- No heater needed (coldwater fish)
- Large surface area for oxygen exchange
- Smooth decorations to protect long fins
- Sand or smooth gravel substrate
- Open swimming space essential
Important: Their long, flowing tails need space. Avoid decorations with sharp edges that could tear fins.
Water Quality
- Temperature: 65-75°F (18-24°C)
- pH: 7.0-8.4
- Water Hardness: Moderate to hard (8-20 dGH)
- Ammonia/Nitrite: 0 ppm
- Nitrate: <40 ppm
Maintenance:
- Weekly 30-50% water changes
- Heavy filtration essential
- They produce significant waste
- Monitor ammonia closely
Feeding
Comets have big appetites like all goldfish:
- High-quality goldfish pellets or flakes
- Sinking pellets preferred (prevents air ingestion)
- Vegetables: Blanched peas, zucchini, spinach
- Frozen foods: bloodworms, brine shrimp (occasional)
- Plant matter: They will graze on algae and plants
Feeding Schedule: 2-3 times daily, small amounts they consume in 2-3 minutes.
Behavior & Compatibility
Fast, active swimmers:
- Best With: Common Goldfish, Shubunkin Goldfish
- Can Work With: Dojo Loaches, White Cloud Mountain Minnows
- Never With:
- Tropical fish (temperature mismatch)
- Fancy goldfish (will outcompete them)
- Slow-moving fish
Behavior: Constant motion, graceful swimmers with their flowing tails. Interactive and responsive to owners.
Tail Care
The long tail requires some considerations:
- Avoid sharp decorations that could snag or tear fins
- No aggressive tankmates that might nip fins
- Good water quality prevents fin rot
- Space to swim without hitting decorations
Common Health Issues
- Fin damage: From sharp objects or aggressive fish
- Fin rot: From poor water quality
- Swim bladder issues: From constipation or overeating
- Ich: White spots disease
- Ammonia poisoning: Most common serious issue
Size & Growth
Comets grow large but slightly smaller than Commons:
- First year: 4-5 inches
- Mature size: 10-12 inches (tail adds significant length)
- Lifespan: 10-20 years in proper conditions
Color Variations
- Red/orange: Most common
- Sarasa: Red and white pattern (very popular)
- White: Pure white variety
- Yellow: Lemon-yellow color
- Black: Rare, often changes color
- Chocolate: Brownish variety
Tank Maintenance
- Weekly 30-50% water changes
- Gravel vacuuming
- Clean filter media regularly
- Test water parameters
- Inspect fins for damage
Tips for Success
- Provide largest tank possible
- Invest in quality, oversized filtration
- Use sinking foods to prevent swim bladder issues
- Feed vegetables regularly
- Never mix with fancy goldfish (speed difference)
- Never mix with tropical fish
- Avoid sharp decorations
- Consider pond life as they mature
- Quarantine new fish
- Secure lid - they can jump
Comparison to Common Goldfish
- Comet: Long, flowing tail, slightly smaller body, more ornamental
- Common: Short, single tail, larger body, slightly faster
- Both: Hard, streamlined, active, coldwater, large tank requirements
Pond Life
Excellent pond fish:
- Minimum: 100+ gallons
- Benefits: More space, natural food sources, temperature stability
- Lifespan: Often exceeds 20 years in good ponds
- Color development: Often better in natural sunlight