Monthly aquarium operating cost depends on size + type + light intensity. 20-gallon freshwater: $8-15/month. Heater + filter + 1 LED + food + water-change dechlorinator. 55-gallon freshwater: $15-30/month. Larger heater + canister filter + medium-output LED + food + supplements + monthly water test reagents. 75-gallon reef: $40-90/month. Two MP10/MP40 powerheads + return + ATO + 2 reef LEDs + protein skimmer = ~$30-50 electricity alone. Salt mix $15-25, RO/DI consumables $5, calcium/alk/mag dosing $10-25, fish/coral food $15. Drivers of cost: electricity rate (CA = $0.30/kWh vs TX = $0.13/kWh), light intensity (high-PAR reefs draw 200-400W), heater duty cycle (cold rooms = constant heater run). Cost-saving tips: LED over T5 or metal halide, wave makers over high-flow returns, lid your tank to cut heater runtime, run RO/DI from house water instead of buying jugs. Use our aquarium electricity calculator for your exact rate.
The full Q&A library answers the most-searched aquarium questions. Browse calculators, glossary, and disease database for related help.
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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