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For an aquarium, a power outage is a life-or-death event: without the filter, heater, and air pump, fish can be lost within hours. A portable power station with UPS mode is the simplest, quietest way to keep a tank alive through a blackout.
The short answer
Aquarium life-support (filter, air pump, heater) draws only 50–250 W depending on tank size, so a 500–1000 Wh LiFePO4 unit with UPS pass-through keeps a tank running for 4–15+ hours and switches over instantly so the water never loses heat or oxygen. Our top pick is the Bluetti AC180.
Why UPS auto-switch is non-negotiable
A true UPS pass-through takes over in milliseconds when power fails — the heater and air pump never skip a beat, even while you are at work or asleep. For aquarium backup this is the single most important feature.
Aquarium power draw & runtime
| Tank setup | Draw | On 768Wh | On 1152Wh |
|---|---|---|---|
| Nano (filter + air pump) | ~15 W | ~43 hrs | ~65 hrs |
| 20–40 gal (filter + heater + air) | ~100 W | ~6.5 hrs | ~9.8 hrs |
| 75 gal (heater + pump) | ~250 W | ~2.6 hrs | ~3.9 hrs |
During a long outage, prioritise the air pump (oxygen) above all — it draws only a few watts and matters most. The heater is the biggest draw; in a pinch, insulate the tank with a blanket instead of powering the heater.
Best power stations for an aquarium
Bluetti AC180
Sub-20 ms UPS transfer, 1152 Wh, and pure sine output keep a mid-size tank alive for the better part of a day and switch over so fast the fish never notice.
EcoFlow RIVER 2 Pro
For nano and small tanks, the 7.8 kg RIVER 2 Pro has UPS mode and runs basic life-support for many hours — easy to tuck beside the stand.
Anker SOLIX C1000
If the tank is in a bedroom, the C1000 is the quietest 1 kWh option for silent overnight backup.
Frequently asked questions
How long can a fish tank run on a power station?
From ~4 hours for a large heated tank up to days for a nano tank with just a filter and air pump, on a 1 kWh unit. Capacity and heater use decide it.
What should I prioritise during a long outage?
Oxygen first: keep the air pump or filter running (a few watts). Heat second — insulate the tank to reduce heater runtime and stretch your battery.
Does it switch over automatically?
Yes, with UPS / EPS pass-through (AC180 and RIVER 2 Pro). Plug the tank gear into the unit, the unit into the wall, and it takes over instantly on outage.
Related guides
- Best Portable Power Station for Apartment Blackout (2026 Guide)
- Best Portable Power Station for Home Office Backup (2026 Guide)
- Best Portable Power Station for Renters (2026 Guide)
- Best Quiet Portable Power Station for Indoor Use (2026 Guide)
Keep the tank alive
For aquarium backup, get UPS pass-through and enough capacity for your tank size. The Bluetti AC180 is the safest all-rounder; the RIVER 2 Pro covers nano and small tanks.