How do I look after my tropical fish during a power cut?
When you have invested a lot of time and money in tropical fish and equipment you need to have peace of mind that they are protected during a power outage. We know tropical fish don’t react well to drastic changes or drops in water temperature – needing between roughly 24-27C* (75-80F) to thrive.
*exact recommended temperature will depend on the fish species
If the power goes off
During a power cut, the water will start to drop to room temperature. Most fish cope well with a gradual rise or fall in water temperature over a 24 hour period and, although they may become sluggish and behave differently, they should make a full recovery. Changes like this happen in nature and only delicate species might be badly affected.
The speed at which the water becomes cooler can be affected by:
- The surrounding air temperature
- The size of the tank and the volume of the water held inside it. For example, a larger volume of water takes longer to cool down than a small amount.
How to protect your fish
Be prepared
If you have received a letter informing you of a planned power cut in your area, plan ahead. We recommend using a cheap bubble-up filter that can be run off a battery-powered air pump during a power cut.
Insulate
For insulation, wrap the fish tank in blankets. If possible, fill hot water bottles with warm water and place them around the outside of the tank. Pay particular attention to the aquarium hood, where most heat is lost.
Oxygenate
Without power, the water will lose oxygen at a rate that depends on water volume, the quantity of fish within the aquarium and whether there are oxygenating plants in it.
Using an ordinary bicycle pump is a cheaper method of moving the water. You will need to do this regularly while the power is off and it is wise to disturb the water surface for five minutes each hour. A good way to do this is by filling a jug with tank water then pour it back in, making as much movement as possible.
Go easy on the food
The tank’s filtration system won’t be working so try not to feed the fish during this time or cut down how much food you give them, to minimise waste.
