White Cloudy Water + Dead Fish After Water Change Help!

[eviltuna]

Hey guys, I have a cycled 46gal bow front tank setup and running with an Aquaclear 70 HOB and Rena XP3 filter. Here are my water paramaters after the water change:

Amonia: 0
nitrite: 0
nitrate: 5ppm
pH: 7.6

Anyways, usually after a water change my water all milky white for 6-8 hours, but on my most recent water change(yesterday) after a couple hours I noticed my fishes acting funning and 1 fish lying at the bottom, after investigation, I found 2 dead fishes and the rest were huddle at the top of the tank gasping for air, so I immediately removed the survivors to my hospital tank and checked my water. I did what I usually do for water changes appropriate temprature, added water conditioner, waited about 20 minutes for everything to settle before turning on my filters again.

Anyways, the water still hasn't cleared today so I decided to do some investigation and after I opened my Rena filter I noticed a funky smell and there was some white growth on the filter and the sponge media. Is this a bacteria bloom? What can I do?

 

[WILDER]

Sounds like to me that something got into the tank like a chemical.

Do you use your water change bucket for anything else.

 

[eviltuna]

I use a Python to change the water.

 

[WILDER]

How long do you think the fish were dead for as that could of caused bad water quality.
I would preform another water change.
How are the fish acting now?

 

[eviltuna]

I would say the fishes died probably 10-15 mins before I checked, after moving the rest into the hospital tank, they are doing fine almost immediately, it seems like there was no oxygen in the water thats why they were all at the top of the tank sticking their heads out of the water gasping for air.

 

[WILDER]

Ok that fine then.
Lack of aeration in the tank would make them gasp.

 

[mikey26]

Hi,

I just had exactly the same problem this morning. I woke up and found a couple of dead fish floating at the top of my tank. I noticed all my other fish where swimming near the top. At first I thought they were just trying to eat the dead fish, but then I realised they were gasping for air. Even my plecos and cat fish were at the top, and I never usually see them. Like you, I'd just done a water change, it was the previous night and about 40-50%, and the water was a little bit cloudy. All I had done different this time was put some Tetra Easy Balance in, as recommended by my lfs... I won't be using it again.

Unfortunately I don't have a hospitcal tank. By the time I left for work there were about 8 fish dead.. including my favourite angel fish. I'm really not happy. I put an airstone in the water, and took out about 25% of the water so it is below the level of the pump output (so the water on the surface is moving around a lot). By then I was really late for work so I had to leave. I just hope all my fish aren't dead when I get back!

How are your fish doing? Have you put them back in your main tank yet?

 

[Yuki_of_the_Stars]

You said there was a funky smell inside the filter? I think it may be bacteria. Like us, bacteria use oxygen in the air and water they survive in. I'd replace the media you have, and clean that filter well. If that don't do it, replace the filter entirely. If this still happens... I'm out of answers.

 

[bodyshop20]

I had this problem a few wks back after water change.
It was some dodgey water conditioner that reacted with medicine in tank i used to kill mouth fungy.
I did a total water change with filter media change for new.
It worked and within 24 hrs my fish was all happy, i only lost 3 fish out of about 200

 

[eviltuna]

What I did was I basicly drained the tank, got rid of all my rocks/substrate and got new substrate cleaned out all the filter sponges and replaced the carbon. The tank is now up and running, everything seems to be smooth now, so overall, I lost 2 fishes, the rest are very healthy and a yellow lab and sunburst peacock both holding now, plus the tank looks much better. I just wished I put in an undergravel jet like i wanted to do originally, but through all the chaos I forgot to do it.