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Powercuts - Precautions and Emergency Measures to Save Your Fish
Published by Violet on 18/12/2010 (23074 reads)
Power cuts! They strike fear into the heart of any fish keeper and are something we try to ignore until we are affected.

This is something we all worry about after all, once the power goes out, the filters will stop running so the filter bacteria start to die off and for tropical fish keepers, the temperatures will start to fall. Larger tanks, holding more volumes of water will remain safer for longer when it comes to temperature though, as larger volumes of water lose heat at a much slower rate than smaller tanks.

The majority of power cuts in the UK are unannounced. That?s means they happen during the night when you are asleep or out during the day. If power is to be turned off for considerable periods, you may be fortunate enough to have prior warning, sometimes days in advance, so you can be prepared.

With special thanks to Dem, for first trialing the UPS and her feedback, there are various emergency tricks for contending with loss of power and these include the following measures:

Option 1 - Battery driven air stones

Filters need a constant supply of oxygen to keep the bacteria alive. Ideally, if you are present when the power goes off, the best line of action is to remove the filter media and house in a bucket of tank water with a little liquid ammonia with battery powered air stones. Both the food source and air supply should keep the bacteria alive until power resumes when they can be put back into the filter housing and tank.

If loss of power exceeds a few hours and whilst the filter media is out of the tank, some Prime or Amquel plus added to the tank water, should keep the fishies safe from any elevated levels of toxins until the filter can be restarted. Once power resumes and you can reinstall the filter, keep a close eye on water parameters for a week or so by testing each day. Some daily water changes may be required if any spikes occur until things settle down again. Alternatively it may be possible to push the tubing and air stone into some types of filter casings, thus keeping flow going without removing the media at all. This will depend on the type of filter you have.

As for conserving temperature, wrap the tank in blankets/big towels or a duvet to help retain heat in the interim.

JAD or Boyu Aquatic Batteries for example, are used by many here and both come with a length of air tube and an air stone

Search Google for Boyu battery
Search Google for JAD battery


This initial course of action assumes you are home (and awake!) of course to take preventative action.

Option 2 - UPS

The Uninterruptable Power Supply! For anyone that isn?t familiar with them it?s a giant battery pack that is generally used to power computer systems short term. It plugs into a standard socket and charges up, for the filter plug. You leave it plugged in 24/7 as it constantly charges whilst mains power is on. If the mains power fails the battery kicks in within a few seconds or so and then runs until flat or (hopefully) until the mains power resumes. Probably best left for the main filter system and possibly the heater only (where an issue) to ensure more longevity. Lighting and air stones will only suck power from such units draining them faster and they are not emergency requirements.

Good FK link here for more information: Aquarium UPS Review on FK

You don?t have to be home, or awake! Peace of mind. Depending which type of UPS you install and the voltage of the filter, run time has now been achieved by two forum members of at least 3-4 hours (possibly more, but power resumed during these tests). Certainly, the APC Back-UPS ES 400VA 230V for example, looked after a Fluval 305 and an Eheim Ecco 200 external filter respectively on two separate occasions, for up to 4 hours. This usually caters for the average unannounced power cut length. If the UPS battery does exhaust, you can resort to option 1 if you are present.

Cost. Currently circa ?70-?80 at the time of writing this article.

Option 3 - Petrol Generators (multiple large tanks/fish rooms etc)

It would be considered overkill by many fish keepers but for those who have large multiple tanks or specifically ?fish rooms?, a hired petrol generator can be obtained when a pre-warned power cut has been advised. HSS Tool hire for example, start them at ?26 for one days hire (2010/2011 prices) that can be run from the back garden with a cable.

Generator on HSS Tool Hire Site

Relative to the amount of stock, cheap to pre-order and run.

Noisy, clunky and you have to be home to start and refuel when needed.
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  • Coldwater Moderator

 Re: Powercuts - Precautions and Emergency Measures to Sav...

Additional information here: ... hp?topic_id=6878&forum=14

  • Home away from home

 Re: Powercuts - Precautions and Emergency Measures to Sav...

Just wanted to tag onto this article regarding UPS systems. I repair computer systems and am familiar with a lot of the tech. You don't need a fancy APC UPS, as a lot of the sophisticated part of this is the PC communication to alert a server of a power cut etc. - unless you have a computer managing your tanks, this wouldn't be needed. Strip that away and you're basically looking at a large "Sealed Lead Acid Battery", "Charger" and "Mains inverter".

If you're electronically minded it's possible to build one, but I wont go into that here.

If you look to companies like Belkin and Trust, they often make much cheaper UPS units which don't have a lot of the communication stuff in them, but would do just as well for a tank.

To work out how long the unit would last, calulate the watts used by your setup. Typically, you probably only power the filter, as the tank should keep its heat over the time of a power cut.

Looking at a ?60 unit specifications it states it contains 2 x 12V 8AH batteries.
2 x 12V x 8Ah = 192Wh
Take off a bit to allow for efficiency of the electronics. I allow 20%.
192Wh x 80% = 153.6Wh (so say 154Wh).
Lets say you have a 10watt filter.
154Wh / 10W = 15.4hours
Of course, if your heater is on there too, it would pull a lot more, but remember the heater is not on all the time.

Say the heater spends 1/3 of its time on, 2/3 of its time off, and it's a 100W heater. You can average that to 33W.

10W + 33W = 43W
154Wh / 43W = 3.58hrs (say 3.5hrs)

If you do go the DIY route, a car battery can be 10x more capacity than that, so could run a far larger setup, or the same setup for much longer.

Hope this is of interest to people.

  • Home away from home

 Re: Powercuts - Precautions and Emergency Measures to Sav...

Note - also consider solar panels. I've seen them drop dramatically in price, and using a 20Watt panel to power an inverter and 10watt filter is not unrealistic assuming it's sunny.

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