overnight death

Last night went to sleep and all my fish were doing great. none of them were showing any signs of distress and i just did a water change a few days ago. water quality was fine. this morning i woke up and their was a strange smell in the room with my fish tank in it. i didn't pay any attention because i thought it was just the dirty water bucket that i left out from a few days ago. about 30 minutes ago i walk into the room and noticed that all my fish are actually dead and my water is slightly cloudy. the tank has been set up for over 2 years and has not had a problem like this. does anyone know any possible reason why a tank would crash like this? thanks for any help.

 

I would really like to know too. My guess would be ammonia or bacteria bloom sucking all the oxygen out of the water suffocating your fish to death. :-(

 

Also can you please post detailed steps on how you do water changes? What salt, prep time, tool for measuring SG ect..


If the only variable is a water change its important to know if something went wrong in those steps.

 

dont think it was the water change i do it the same way every time mixing a 5 gallon bucket 24-48 hours in advance with a pump and a heater in it. always make sure sg is almost exactly the same before i siphon the new water into the tank. plus when i say a few days what i really meant was about a week. i don't know what could be in my tank that would cause an ammonia spike like that. all i have are 4 clowns and 1 lawnmower blenny. no dead fish until today and even their dead bodies don't look like they had any visible signs of finrot or anything.

 

Tank volume? Waste export method? Sump? HOB? ?

Sorry for your loss

 

+1. Oxygen levels area decreased at night. One fish death in a nano tank causes a cascade effect, causing another fishes death and so on and so on.
As decay sets in the bacterial filter is over whelmed and can not keep up leading to unstable water chemistry.

This was a Nano correct?

This is not a heater issue or malfunctioning pump issue I presume?

 

Probably oxygen levels. Things can go from fine to horrible super quick when your dealing with a very small volume of water.

 

pH

Hello sorry for your lost , once my PH got so low that my. Fish started dying at bottom of tank , did you check your ph ,it was also after I did a water change ,

 

Sorry bout your fish.

Does your tank has a lid/cover/brace?

I was told by an experienced reefer that if you fill your tank too high where water touches the lid/brace, it can stop gas exchange between water and air suffocating your fish.

Also, how deep is your sand bed/substrate? If it's deeper than 2 inches, is it possible that something stirred it up? That can release build up gasses that are poisonous.

 

sad...... it can be sg, if not tht, thn o2..