power out

[Madmak]

Water temperature is what changes the fastest and is what kills things first. 200 gallons will hold heat for quite a while if the house is still heated. If both don't have power you don't have too long. My guess would be some losses starting at 24 hours and getting worse from there.

If your there and can wrap blankets, add an air stone, etc you might have 48 hours before the badness begins.

Good question.

[sphelps]

IME when it comes to fish it's low O2 that will kill first, temp unless you have a small tank shouldn't be an issue. Some sort of battery back up for a powerhead or air pump can make a huge difference.

[jagermaier]

Originally Posted by sphelps

IME when it comes to fish it's low O2 that will kill first, temp unless you have a small tank shouldn't be an issue. Some sort of battery back up for a powerhead or air pump can make a huge difference.

Agree 100%, oxygen is the most important part of keeping your fish alive! Battery back up on power heads most important!