Temperature effect on BB

[Scrup]

Does a rapid temp change kill bacteria?

I just cleaned out both my big tank and my goldfish tank/s filter media (not all of it, just the sponge portions) in my pond that I am letting cycle, in the hopes it would help things in the pond along. Was full of dechlorinated water that was in the pond for the last week running steady. Low and behold this morning I see one of my goldies dead on the bottom. Check the water, ammonia is off the scale (didnt pay attention to the numbers, I just know I've never seen it that dark green before... ).

Check the big tank, same thing, only not quite as bad (I imagine guppies produce a little less waste than goldfish )

Nothing like early morning "HOLY #$%#" water changes.

The outside pond is running at probably 40 degrees right now, whereas the inside tanks are both running steady at 60 (goldfish) and 80. Both tanks got 30-40% water changes not 4 days ago.


The only thing I can think of is I didn't put enough dechlor in, but in fact I usually overdose it a little, plus running for a few days with good aeration should have cleared it up.

So water changes, careful monitoring and I will seed them from the other tanks I have in the hopes it clears up in time. Really glad I started keeping extra filter media in all the tanks just for something like this.

Any thoughts on what could have happened?

[Algenco]

if you didn't use enough dechlor it would have killed at least some of the bacteria and would have dissipated by the time you noticed a problem

I killed 50 pelvichromis teniatus fry that way

[gadget228]

In one of the many threads I read on doing a fishless cycle it did mention that turning the tank temperature up would help the beneficial bacteria grow and that when the cycle was complete to reduce the temperature slowly over a couple days because a sudden large change would kill the beneficial bacteria off.