Free tank cycling timeline calculator. Enter tank type + bacteria source, get the estimated days to complete cycle. Plan your stocking date with confidence.
Cycling speed depends on bacterial seeding source + temperature + ammonia source. Live rock from a mature tank is the fastest seed (sometimes 1-3 days "instant cycle"). Bottled bacteria (Dr. Tim\'s, Bio-Spira, Stability) speeds the cycle to 7-14 days.
Cycle complete signal: dose ammonia to 2 ppm; if it converts to 0 ammonia + 0 nitrite within 24 hours (with nitrate present), the cycle is complete. Do a 50% water change before adding fish.
Browse the full calculator library for tank stocking, water change, dosing, PAR, electricity cost, heater sizing, CO2 BPS, salt mix, and more.
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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