Rummy Nose vs Cardinal vs Neon Tetra Comparison Guide: Schooling Picks
Three classic schooling tetras anchor most planted tank stocking lists, and choosing between them is harder than the colour photos suggest. The rummy nose vs cardinal vs neon tetra decision balances water hardness, schooling tightness and budget — get it wrong and you end up with washed-out fish that hide. This guide from Gensou Aquascaping at 5 Everton Park ranks the trio against Singapore PUB tap and Iwarna pricing.
Quick Verdict
Pick rummy nose tetra for the tightest, most disciplined school in a 90-litre+ planted scape. Pick cardinal tetra for maximum colour saturation if you can run softer, slightly cooler water. Pick neon tetra as the budget hardy option for community tanks where you cannot dial in soft acidic parameters.
Rummy Nose Tetra: The Disciplined Schooler
The rummy nose tetra (Hemigrammus rhodostomus) reaches 4-5cm with a translucent body, candy-cane red head and black-and-white striped tail. They are obligate schoolers — singletons go pale and refuse food. Group of 8 minimum, 12+ for proper formation swimming. Water demands: pH 5.5-6.8, GH 1-6, temperature 24-27°C. Rummies are the canary of the planted tank — when stress shows, the red nose pales within hours, giving you an early warning of water issues. They reach colour intensity around month four after acclimation.
Cardinal Tetra: The Saturated Showpiece
The cardinal tetra (Paracheirodon axelrodi) hits 4-5cm with a vivid blue stripe running the full body length and a deep red belly extending nose-to-tail. They demand softer water than neons — pH 5.0-6.5, GH 1-4, temperature 23-27°C — and the bottom of that temperature range is where the colour pops hardest. Singapore ambient pushes the upper edge in summer. School of 10+ minimum. Cardinals are wild-caught from the Rio Negro for the most part, so quarantine and gradual acclimation are essential.
Neon Tetra: The Budget Hardy Option
The neon tetra (Paracheirodon innesi) reaches 3-3.5cm — slightly smaller than cardinals — with the iconic blue stripe but red only on the rear half of the body. They are tank-bred globally and tolerate a much wider pH 6.0-7.5 and 20-26°C. Singapore-bred and Eastern European tank stock handles PUB tap straight after acclimation. School of 10+. Watch for “neon tetra disease” (a microsporidian parasite) in farmed stock — quarantine new arrivals for 14 days minimum.
Side-by-Side Spec Comparison
Size: neon 3.5cm, cardinal and rummy nose 4-5cm. Hardness tolerance: neon widest, rummy nose narrow, cardinal narrowest. Schooling tightness: rummy nose discipline-tight, cardinal moderate, neon loose. Singapore PUB tap suitability: neon excellent, rummy nose moderate, cardinal poor without remineralisation. Price: neon SGD 1.50-3 each, rummy nose SGD 3-5, cardinal SGD 4-8 with wild-caught at SGD 8-12. Bioload across all three is light.
Decision Framework
If your tank is under 60 litres, pick neon — the smaller size keeps stocking sane. If you want the tightest school as a focal point in a Dutch or nature aquascape over 90 litres, pick rummy nose. If you specifically want the most saturated tetra colour and you have RO/DI water or aged peat-conditioned water, pick cardinal. For a mixed-tetra display, neon plus rummy nose works because the colour patterns complement; avoid mixing cardinal and neon since they look like inferior versions of each other.
Singapore Sourcing and Pricing
All three are Iwarna and Polyart staples. Tank-bred neons run SGD 1.50-3 each in packs of 10. Rummy noses sit at SGD 3-5 each, with imported Czech stock around SGD 5-7 holding better colour than mass-bred lines. Cardinals split into farmed (SGD 4-6) and wild-caught Rio Negro (SGD 8-12). C328 Clementi and ANS stock rotate weekly. Pair them with botanicals and a stable mature filter from the aquarium filter range for best colour results.
Common Mistakes
Buying schools of 5-6 is the universal beginner error — all three species need 10+ to school properly. Second mistake: dropping cardinals into a hard PUB tap community without remineralisation; expect 30-50 per cent losses within 30 days. Third: mixing rummy nose with aggressive fin-nippers like serpae tetras or tiger barbs — the long flowing fins get shredded. Fourth: lighting bright bare tanks washes all three out. Use floating plants and a dark substrate from the substrate range.
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