Fish pricing spans 4 tiers + a luxury market. Budget tier ($2-15): guppy, neon tetra, cherry shrimp, white cloud minnow, danios, common goldfish, common platy/molly, common corydoras, otocinclus, mystery snail. Pet store + chain availability. Mid tier ($15-50): dwarf gourami, German blue ram, kribensis, ember tetra (designer), plakat betta, fancy goldfish, ottos, rummy nose, corydoras (panda, sterbai), clown loach (juvenile), royal gramma, mandarin dragonet, banggai cardinal, cleaner shrimp, common clownfish. Premium tier ($50-300): fancy bettas (HMPK, dragon-scale, koi-marble), discus, designer guppies, captive-bred angelfish (named lineages), apistogramma species, yellow tang, blue tang, flame angel, anthias, fairy/flasher wrasses. Luxury tier ($300-3,000): show-grade discus, designer clownfish (snowflake, naked, etc.), large angels (queen, emperor adults), Achilles tang, large koi, rare wild-caught wrasses + anthias, custom plakat lines. Trophy tier ($3,000-100,000+): show koi (kohaku, sanke from named bloodlines), arowana (asian platinum, super red), peppermint angelfish ($30,000), rare reef fish. Tip: WYSIWYG photographed-before-buy stock costs 30-50% premium but you see exactly what arrives.
The full Q&A library, calculators, diseases, glossary, and interactive tools answer the most-searched aquarium questions.
Whatever specific topic brought you here, four fundamentals govern long-term aquarium success: water quality, parameter stability, biological filtration, and species-appropriate husbandry. Skip any one and the others struggle to compensate.
Water quality: ammonia + nitrite at zero, nitrate under 30 ppm freshwater + 10 ppm reef. Test weekly with API or Salifert kits. Use our water parameter checker to score your readings against your tank type.
Parameter stability: stable wrong parameters beat fluctuating ideal parameters. Most fish tolerate a wide pH range if it's stable. Sudden swings of 0.4+ pH or 5+°F kill fish faster than chronic suboptimal values. Use temperature controllers (Inkbird) + automated dosing for consistency.
Biological filtration: the bacterial colony on your filter media + rock + substrate is the engine. Never replace all media at once. Use our filter turnover calculator to size correctly.
Species-appropriate husbandry: research adult size, territoriality, diet, and tankmate compatibility before purchase. Use our tank stocking calculator + compatibility guides.
How long does an aquarium take to set up? 4-6 weeks for full cycling + first stocking. Use our cycle ETA calculator + how long does cycling take.
What's the best aquarium for beginners? 20-gallon long. Big enough for parameter stability, small enough for budget + space. See beginner picks.
How often should I do water changes? 25-30% weekly. See water change frequency Q&A + water change calculator.
Why does my fish keep dying? 5 leading causes: uncycled tank, wrong species pairings, no quarantine, undersized tank, neglected water-change schedule. See full diagnosis.
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