Fish die Overnight

[Eelzor]

My fish are not dead, but in the past I realised that all the fish I had (before I Knew about cyling etc) always died overnight. Is there a reason for this? Never in the day, always at night, or when I am not looking. Why? Or was it all just a big coincidence?

 

[FrankSlapperinni]

I think its because fish go into a sort of stasis over night, their not exactly sleeping, but their not exactly awake either. most fish that are sick will probably "go to sleep" at night with the other fish.

 

[rykitten]

I don't know about that . . .
It seems they like the lights off. They become mischevious.
I had a sick swordtail with a fungus patch on his back. I left work for an hour and turned out all the lights. When I came back, the fungus was gone and the swordtail had a huge hole in his back.
Correct me if I'm wrong . . .
But I think some fish like privacy. It gives them an opportunity to do things they wouldn't do if a human was watching.
They are too busy watching us back!

 

[EddieW]

Could possibly be an oxygen issue? When lights are on the plants are using up carbon dioxide and producing oxygen, when they are off they are using up oxygen and producing carbon dioxide - if the tank is low on oxygen or the fish is 'on the edge' the reduction in oxygen might be a factor.

Just a thought, Eddie

 

[Kossy]

I wouldn't think so because don't forget your filter is moving the current around...allowing oxygen to mix into the water. Plus many people have fake plants (which I'm against) but it doesn't seem to affect the levels. When I had my first ever cycling problem (ages ago ) I remember only my betta died...my cory was sick but pulled it through (and is still alive as i write and is pregnant too) that happened over night, also my danio's died at approximately 2 day intervals... hence mine didn't occur over night. But like i said this was ages ago

 

[Corp000085]

Could it be a temperature issue? Most people turn their furnace down at night. Plus, the hood light generates heat. Are your dead fish known to not tolerate temperature changes?

 

[Eelzor]

Corp- My fish aren't dead, just in the past they did such.

FrankSlap.-I think I agree with yours the most on this one.