DOA is the standard livestock-shipping term for a specimen that arrives dead or dies within a defined claim window after delivery. Most aquatic vendors offer a 4-hour DOA guarantee starting at carrier-reported delivery time.
Practical use in aquariums
Fast Aquatics standard: 4-hour DOA window with photo evidence required, processed within 24 hours. Climate-aware shipping holds the order if forecasted temperatures at the destination ZIP exceed safe thresholds. Browse Buyer Protection for the full claim process.
How DOA fits the bigger picture
Understanding DOA matters because it's connected to broader husbandry decisions: sourcing decisions echo for years: a hardier captive-bred specimen pays back its premium in lower mortality + faster acclimation.
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.
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.