Did A Huge Water Change Without Adding Dechlorinator

[kelp]

My fish are either upside down breathing deeply on the gravel, or they are at the top gasping for air. I just did a 40% water change in my 29 gallon tank, and my fish are going crazy. I usually do a 25-30% water change without adding dechlorinator with no adverse effects, but I guess an extra 10% was really pushing the limits. What can I do to save the fish?! I've already added dechlorinator. I wish I had another tank I could scoop cycled water from. Speaking of cycled water, yes this tank is cycled, I've had it running since January.

 

[WILDER]

Increase aeration.
Might have had heavy metals in your water.
Have they clamed down since you added the declorinatorl.
Find you some info if I can.

http/www.tropicalresources.net/phpBB2/d_..._chloramine.php

 

[kelp]

They still haven't calmed down. I'm pretty sure one of my Harlequin's is dead on the gravel. Another one is laying beside him breathing heavily upside down. I've put up the air pump to try to stabilize the oxygen.

 

[Christine1014]

I definitely wouldn't continue the habit of not using water conditioner. Unless you have well-water, the chlorine in the public water supply can kill off your good bacteria which means you're tank will have to cycle again. An occasionally couple of gallons probably isn't enough to wipe out the bacteria, but I wouldn't make it a regular practice. My fingers are crossed for your fish!

 

[Tolak]

What are you using to condition the water?

 

[kelp]

It's called Aqua Plus. I've lost a corydora and four harlequin rasboras leaving me to 2 harlequins.

 

[Tigermoth]

I doubt it's a simple case of killing off the bacteria in the filter/water, although it's possible.

It's also unlikely to be a water temperature shock at this time of year.
It's more than likely the chlorine in the tap water has reacted with the ammonia that's built up in the old tank water and has produced chloramines, which has seriously shocked the fish. I'd say do another water change with dechlorinated water, quickly.

 

[Danno]

It might be a whole new reason. Check your pH ammonia nitrate and nitrite.

 

[WILDER]

I agree as the ph of the tap could of been different to your tank.
There not much to be done apart from increasing aeration.