Fish Dying After PWC

[ragin1cajun]

I have a question, after a couple of the weekly PWC that we have done we have had a couple of zebra danio's die on us.

The process we are following is:

1. Using the python we have taken out roughly 40-50% of the water.
2. Add Prime to the tank. (Full Tank dose)
3. Add water back in guestimating the temperature of the water. Prior to PWC water temps were 78 degrees and after 79-80 degrees.
4. Add Seachem Flourish while the water is filling for the plants.

The only thing I did differently this time is my daughter and I took out the java fern and attached it to a new piece of driftwood with thread. We then put the driftwood in the tank for the first time.

After the PWC, the Danios sit at the top of the water with their mouths at the top. They eventually turn upside down and die soon after.

Are we doing anything wrong? I have done a lot of reading here and elsewhere since getting the fish and I cannot think of anything?

Any advice would be greatly appreciated!!

 

[mastro80]

I would say that you have probably done a bunch of water changes before, but this is the first time you added driftwood. My guess would be the driftwood was the source of your problem. It is the only variable you added to the equation according to the story.

 

[Dragonwolf]

Possibly the thread? Could be dyed. Or like Mastro said, the driftwood. Did you boil the driftwood before putting it in the tank? I didn't with mine because it came right out of a tank at the pet store. But I have read a lot of posts where people say they boil the driftwood before putting it in the tank.

Hope you get it figured out!

 

[ragin1cajun]

I do not think it was the driftwood or thread simply because the 2 fish starting showing symptoms literally at the same time or within just a couple minutes of putting the driftwood in the tank and turning the water on to fill the tank.

I would think (I could be wrong) that it would take more time than that if it were one of those two things to cause a problem for the fish.

I forgot to mention that I tested the water before doing the PWC and the levels were:

pH: 8
Ammo: 0
Nitrite: 0
Nitrate: 20-40

The only thing different than normal is the pH of 8 is higher than the 7.4 the last time I tested 1 1/2 weeks ago.

David

 

[jlk]

Did you check your tap to see if anything has changed? Do you have public water? Another guess is your supplier has changed something in how they process the water since your last water change. Perhaps they switched disinfectants, manner it's processed, the source or happened to be flushing the system prior to the wc. I doubt it was the thread or the dw unless it had been soaked/exposed to some sort of toxin. Just throwing some possibilities out there- I hope you can figure out what happened!

 

[thomasina]

What kind of container held the water that you used to fill the tank? Sometimes it has something in that is bad. I boiled my drift wood for three days until the water ran clear. Where did the DW come from? and What kind was it?