Zebra Danios dead after water change

[Mixer]

I did a 50% PWC after testing my water. Ph 7.6, ammonia 0, nitrite 0, nitrate 20 ppm. I have had these zebra danio for about 4 days, I also got some neon tetras at the same time, I had lost a couple of tetras since i got them, which is pretty normal I think, they are such weak fish.

I had not lost any of the danios so far, until did the water change, and then BOOM two of them dead within 2 minutes of the change.

Did I do something wrong? Has anyone had this happen?

 

[roydooms]

I did a 50% PWC after testing my water. Ph 7.6, ammonia 0, nitrite 0, nitrate 20 ppm. I have had these zebra danio for about 4 days, I also got some neon tetras at the same time, I had lost a couple of tetras since i got them, which is pretty normal I think, they are such weak fish.

I had not lost any of the danios so far, until did the water change, and then BOOM two of them dead within 2 minutes of the change.

Did I do something wrong? Has anyone had this happen?

That happened to me with some of my cardinal tetras. I did a PWC and planted a few new plants. I think I stirred some of the detritus, went to the water column and killed the fishes. That was only my theory. Did your water temp dropped while doing PWC?

 

[mudraker]

How did you dechlorinate the water?

 

[siva]

Maybe you accidently added cooler water than you meant to? It sounds like the water may have been too cold and they went into shock. How are you temping the water for your changes?

 

[Mixer]

Prime, 4ml for a 36 gallon tank. Put it in the tank just before I started adding water.

 

[roydooms]

Prime, 4ml for a 36 gallon tank. Put it in the tank just before I started adding water.

What is your tanks temp? What was the newly added water temp?

 

[Mixer]

I guess it could have been a temp issue, don't really have a way to test temp before adding other than just feeling it and trying to be just cool to the touch.

How do you check the temp of yours?

 

[roydooms]

I guess it could have been a temp issue, don't really have a way to test temp before adding other than just feeling it and trying to be just cool to the touch.

How do you check the temp of yours?

It's either I use a thermometer or by touch(test the tank water then the water from the faucet).

How do you add your water? Hose from a faucet with hit and cold? Do you use a python?

 

[roydooms]

Don't you have a thermometer in your tank? Just borrow it and use it to test the new water.

 

[Shadowraven]

It could be thermal shock, pH shock, tap water quality or the water not being completely clear of the chlorine/chloramine.

If I need to add water to the tank right away, I prefer to mix the water conditioner thoroughly with the new water and let it sit for a couple of minutes before I add it to the tank. A thermometer is the best way to check the temperature.

Check the parameters of your water out of the tap to see what the pH is. It may be radically different from that in the tank. If it is, then that is the likely culprit.

 

[WendiDell]

I had that happen to me with some new Pearl Danios. I did a 25% PWC. And 2 hours later they were all dead. I was at a loss, nothing like that had ever happened to me like that before.
It turned out that on that particular day, the city water had something go wrong. The water co. didn't say what was in the water, only that it supposedly wouldn't hurt humans, But that it may cause problems with some plants and fish, if you have them.
I had to tare down and wash everything in 1 10g tank where I had the Danios in QT And a 55g tank with only 2 fish in it. The Angel and the Pleco survived but they were burned by what ever was in the water. They are both fine now.
My point is, we can do everything perfect, temp., 0 ammonia, 0 nitrites, 20 nitrAtes, perfect pH , doing regular PWC, and wham everyone dies anyway because of a mistake at the water company.
There are some things beyond our control. Even in the artificial environments we make for our fish.
Try not to blame yourselves for every death. There may be no one at fault. Bad things happen.

 

[Shadowraven]

I had that happen to me with some new Pearl Danios. I did a 25% PWC. And 2 hours later they were all dead. I was at a loss, nothing like that had ever happened to me like that before.
It turned out that on that particular day, the city water had something go wrong. The water co. didn't say what was in the water, only that it supposedly wouldn't hurt humans, But that it may cause problems with some plants and fish, if you have them.
I had to tare down and wash everything in 1 10g tank where I had the Danios in QT And a 55g tank with only 2 fish in it. The Angel and the Pleco survived but they were burned by what ever was in the water. They are both fine now.
My point is, we can do everything perfect, temp., 0 ammonia, 0 nitrites, 20 nitrAtes, perfect pH , doing regular PWC, and wham everyone dies anyway because of a mistake at the water company.
There are some things beyond our control. Even in the artificial environments we make for our fish.
Try not to blame yourselves for every death. There may be no one at fault. Bad things happen.

Too true. I heard of it happening more than once, especially when there was a water main break and the water became contaminated. Your tap water can sometimes be the killer, you can't always rule it out.

 

[Rokuzachi]

PH shock is a pretty fast killer. Test your tap's PH, then the tank. Mine shows a huge difference (Tap = ~10.0, Tank = ~7.4).

In my experience, temperature changes aren't a big deal unless they are really big, or you have sensitive fish. Not saying you shouldn't care about the temp, but I've found PH shock to be much nastier.

 

[saffa-man]

thats really wierd danios are normally the herdiest fish i know

 

[Mixer]

It's either I use a thermometer or by touch(test the tank water then the water from the faucet).

How do you add your water? Hose from a faucet with hit and cold? Do you use a python?

I use an aqueon water changer to change the water. I guess that is like a python.

 

[Mixer]

thats really wierd danios are normally the herdiest fish i know

Well besides the danios issue, I have had a neon a day found stuck to the intake of my filter. I am trying to figure out if this is an issue with the power of the intake, or if they are dying and then getting sucked up.

I have barbs and dwarf gourami and a Molly that seem to be doing great, so I am a little baffled as to why this is a tank of death for tetras.

PS. I haven't had anymore danio deaths since the 2 after the water change.

 

[Shetland James]

I use an electronic thermometer to get it roughly the same. Remember though that where tropical fish live there will be rain which will be cooler than the water itself so fish aren't completely unused to water temperature fluctuations.

Fish tank fish are incredibly spoilt compared to their wild relatives.

 

[mfdrookie516]

Mixer, I do it the same way. It doesn't sound like you did anything wrong. I'd suspect the tap water had something funky going on... or it was purely a coincidence and the danios would have died regardless of whether you did a pwc or not. As far as the neons, the filter intake isn't too strong. Even fry can escape the power of the intake... as long as they're healthy. Unless you have something big enough for a 500 gallon tank, I highly doubt your filter is the cause.

 

[kenny69]

Well besides the danios issue, I have had a neon a day found stuck to the intake of my filter. I am trying to figure out if this is an issue with the power of the intake, or if they are dying and then getting sucked up.

I have barbs and dwarf gourami and a Molly that seem to be doing great, so I am a little baffled as to why this is a tank of death for tetras.

PS. I haven't had anymore danio deaths since the 2 after the water change.

Tetras have a 12 month life span, that's why they die so often. You may buy tetras that are already 9 or 10 months old and wonder why they only live for several weeks, 12 months is all they have.

 

[Kat1103]

first and foremost, you didn't need to do a 50% pwc if that's what your readings were prior to the change. You shouldn't do more than 20% IMO. Oh, and I don't think a lot of danios they sell are that healthy anyways. I bought a few a while back and when I got home noticed one was missing an eye, one a fin, and one had a curved spine.