Help, Fish Dying, No Obvious Cause (Picture)

[sadguppy]

On Sunday the filter seal went and poured 75% of the water from a 240l tank over the carpet. The fish survived, we topped the tank up then we had move to a new location so the carpet could be ripped up. That was Tuesday night. Today we have had at least four deaths in the rainbow tank, two Bosemani, one red and one dwarf neon. They have all happened today which is odd as the accident happened Saturday and it was Tues night that we moved the tank - it's been two days now and all stats are fine... 0 ammonia, nitrite and nitrate matches tap water.

I've done a water change and added an air stone but I'm at a bit of a loss at what else to do. I don't want to transfer the fish in case of disease. The remaining inhabitants look ok but then the Bosemani all looked ok when I went out two hours ago yet two have perished. I am hoping that there will be no more casualties but I'm baffled, what could it be? The only thing I can think of is a ph swing due to changing so much water at once when we had to refill the tank after it lost over 2/3 of it's water but that seems a bit out there as rainbows love big water changes so it wasn't more than double the usual change. The fish aren't showing any sign of disease or distress. They're coloured up (even post mortem, see sad photo!) and not gasping for air as you might expect. I'll do another bucket in half an hour and keep doing that.

I need wine.
Oops photo not attached...here goes

 

[cs9]

Sorry for being really basic and patronising but did you dechlorinate the water that you used to refill the tank with?

 

[sadguppy]

Haha yes of course! I've dosed a capful of prime just in case it helps but it was basically just like a very, very big water change...or two very big changes in a row (once when we topped up and once when we moved it). Tank has been set up years.
I'm thinking it must be ph shock but I don't know what the symptoms are. But if it is, surely more water changed won't help?... Or a contaminant but I can't think what.

Either way I would have expected instant death, not 48hrs later!

 

[cs9]

What was the temperature change like? I don't know anything about rainbowfish but I know some fish react badly to fluctuations in temperature. 
I lost some Rams when I had to do an emergency refill like you as they seemed to go into shock upon contact with the cold water that I added and died about 24-48 hours afterwards...

How are the rest of the fish coping?

 

[sadguppy]

I thought it might be something to do with the ph so have changed in some water from another established tank.

My husband was in charge of temperature matching but maybe that's it, in which case are they already as good as dead?! They don't appear to be behaving oddly. No skulking on the substrate.

 

[cs9]

That sounds like a good precaution to take! If they are still going now (is it up to a decent temperature now?) Obviously rams are super sensitive to everything really and I think it was the initial shock that did for them so I would hope that yours would be ok as I had other fish in the tank that survived!
That sounds encouraging then fingers crossed! 

Have you added anything new to the tank recently? Or been treating it with any chemicals regularly?

 

[sadguppy]

There were two new Bosemani rainbows added the day of the carpet disaster (I believe it was cack handed reaching for the light switch to turn it off that did for the filter!) but they're both alive and well - it's the ones I've had for months that have had it! The first fatality, a red rainbow, I've had for years. Very sad about them all really, this is the worst disaster in term of fish lives and definitely ££ (still waiting on quotes for the carpet!) that I've had since starting the hobby a fair wee while ago now.

I took some photos this morning for my really not very well updated fish journal (in my sig) and I've studied the photos, there's not sign of anything wrong at all! So frustrating!

 

[cs9]

Perhaps they have introduced some illness into the tank? Did you QT them? 
It is awful losing fish especially with the carpet damage adding insult to injury! Hope it all works out for you!

 

[sadguppy]

I have to be honest, I don't QT fish as I just don't have the space or equipment for another set up and this is the first time in four years I've encountered a problem like this.
 
Anyway doesn't look like there are anymore deaths - touch wood- so hopefully they can ride it out! I can't face burying such pretty fish! Ive got to admit, I didn't cry at all at the carpet but losing four rainbows in a day, I did crack the wine open and have a sob.

 

[cs9]

I don't have the space or money to QT fish either and I'm like you, very rarely have any issues with health.. 
Hopefully it isn't going to do any more damage to you or your fish, good luck!

 

[sadguppy]

We've had three more deaths overnight, one I actually witnessed - the fish was swimming upside down before it died. Still no clues, it must have been temperature shock but this is three days ago now! I'm just hoping that's it, it's making me very sad indeed!

 

[gh74]

Hi.I know the feeling and what your going through,i had 2 pink tail chalceus die on me yesterday hours apart from each other no signs of illness,then one of the new rams i bought yesterday...longfin gold ram....found dead this morning,i believe that it was temp shock as i unplugged the heater lastnight as it was reading a bit high,then forgot to turn it back on and the temp was reading 23.6 but all the other fish are fine.

 

[sadguppy]

A week after the change and they're still dying, one or two a day... Water is reading fine, don't want to cause more aggro by doing another change, water is a good temperature... Very very depressing!

 

[gh74]

Very strange what fish have you in the tank at the minute? are they showing any signs of illness etc

 

[sadguppy]

There are six loaches and two plecs, all fine. Then there is one remaining red rainbow and four Bosemani - the rest have died - five red and three Bosemani I think. A few dwarf neon rainbows left, there were twelve. It's been a disaster of epic proportions!