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Canister filter lost power for a day, causing fish to die now?

1837 Views 7 Replies 6 Participants Last post by  Greggz
Canister filter lost power overnight, causing fish to die now?

Would a canister filter that was just cleaned out yet lost power overnight then powered on again cause the fish to die? If so, what would be the remedy?

Thinking about running some UV filters to possible sterilize the water.

What would be your advice?

Thanks.
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Probably more due to an ammonia spike from anaerobic bacteria buildup in the canister while it was off. I'd dose the tank with Prime or other ammonia neutralizer.

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Does the canister output create surface agitation?

If so, the fish could easily have died from lack of oxygen.

I seriously doubt they would die from something like ammonia from being off a few hours.
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Many times I've got power outs at home, sometimes for like 12 hours. Never had any problems. I agree with Greggz that bigger problem would be the lack of oxygen without surface agitation.
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I don't believe the canister being off is the issue. I agree with nel. I've had a few 24 hour power outages during winter (I live in central Michigan) without any I'll affects on fish. The biggest factor their was water temp though. If the decreas in temp is very gradual, our fish can withstand a lot colder temps that we think. Most fish go through a hibernation cycle of sorts when they begin to cool down too much. Re-heated the tank slowly to prevent shock and everything went on without a hitch.

A lot of things can happen to our tanks during a power outage and some major things we need to consider regarding a power outage are: water circulation, water temperature, and gas exchange (oxygenated water).

Some more info like tank specs(size, substrate, water parameters, etc), fish species (type and quantity), how you cleaned the filter prior to no power, how proficient and frequent your maintenance routine is(water changes, fert dosing, co2?)

From my experience, I'd pin it down to either poor oxygenation or a quick substantial temperature swing.

Unless notoriously delicate, fish are actually a very hardy and resilient animal and when they die in our tanks it's usually because of an extreme circumstance like suffocating fish with co2 injection, large amounts of ammonia from lack of biomedia/maintenance, temperature shock during poor acclimation, a heater sticking "on", etc.

Water changes are indispensable when trying to overcome tank issues. When in doubt, do some water changes.
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Does the canister output create surface agitation?

If so, the fish could easily have died from lack of oxygen.

I seriously doubt they would die from something like ammonia from being off a few hours.
I have an 2 air pumps and a bubble wand in the tank.
I have an 2 air pumps and a bubble wand in the tank.
Did only the filter power off or was it all the equipment...?
I have an 2 air pumps and a bubble wand in the tank.
I still highly doubt the filter being off had anything to do with it. You could keep fish a tub for days as long as there is oxygen.

You mentioned you cleaned the filter. Did you use anything to clean it with? Just wondering if you induced something into the water. It would make more sense.

As an example, sponges not clearly marked aquarium safe can wipe out a tank in hours. Not saying this is the case at all, just to show odd things can happen.

Hope you figure it out so it isn't repeated again.
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