Buying Aquarium Fish by Mail Order: What to Check Before You Order
Short answer: a fish ordered by mail often spends twelve to forty-eight hours in its packaging before reaching you, compared to a few dozen minutes for a standard trip from the pet store, which calls for extra precautions before and after ordering. A review by Sampaio and Freire published in 2016 in Fish and Fisheries (research on Google Scholar) shows that water quality inside the bag progressively degrades with transport duration, a stress factor that builds up even more over a postal trip lasting several hours. Find our other pointers in the travel and safety section and on the fishkeeping hub.
What should you check before placing an order?
Recent reviews on the mortality rate on arrival, the shipping method used (with or without a pure-oxygen bag, insulated packaging) and the guaranteed time between dispatch and delivery are the three criteria that separate a reliable seller from an unnecessary risk for your future fish.
Should you prepare a receiving tank before delivery even happens?
Yes, the destination tank must be cycled and at the right temperature before you order, not after: a fish weakened by a long transport has no margin left to also tolerate an ammonia spike. See our guide on water tests and the nitrogen cycle to check this point before ordering.
How do you acclimate a fish that arrived by post?
The method stays the same as for a fish brought home from a pet store, with an even more gradual acclimation given the accumulated stress: our guide on drip acclimation details the steps to follow when you open the parcel.
Which season is best for this kind of order?
Avoiding periods of extreme heat or cold limits the risk of thermal shock during postal transit, since a parcel can sit for hours in an unheated or non-air-conditioned vehicle or depot depending on the weather.
- Postal transport often takes twelve to forty-eight hours, far longer than a standard trip from the pet store
- Check the shipping method and guaranteed delivery time before ordering
- The receiving tank must already be cycled by the time you order, not after delivery
- Avoiding orders during a heatwave or hard freeze limits the risk of thermal shock
Frequently asked questions
Do reputable sellers guarantee fish that arrive dead?
Most reputable sellers refund or replace a fish that arrives dead on presentation of a photo, provided you notify them within hours of delivery.
Should you order on a specific day of the week?
Yes, favouring a shipment early in the week avoids a delayed parcel sitting in a closed sorting centre over a whole weekend.
Can you refuse a parcel that arrives visibly too cold or too hot?
Yes, opening the parcel immediately on arrival to check the water temperature is the right reflex, even before acclimation.
This guide is part of Planète Pets’s Fishkeeping universe. Our advice is general in nature: for any health concern, your veterinarian remains the only reference.