6 New Zebra Danios, 3 dead, one not swimming well

[Lexiih36]

Hello I am new to fish keeping. I purchased a 20 gallon tall tank a few weeks ago. Today I bought 6 Danios and put them in. Within the first hour 2 we're dead. They were swimming with their nose to the surface and eventually sank down and didn't go back up. The third died the same way a few hours later.

The 4th one does sink and rest at the bottom while gasping. Another one sometimes swims slightly tilted. The last one is the only one that seems to be fine. For now.

For water parameters there is not ammonia or nitrites. Nitrates stand around 15ppm. Ph is around 7.4-7.6. Temp is 79F. I have a filter and it's at the highest setting because I don't have tubes for my air pump. The tank is also full of live plants.

Any idea why they keep dying?

 

[Oblio]

Welcome to TFF!

Did you condition your tap water?

 

[Lexiih36]

Welcome to TFF!

Did you condition your tap water?

Yes. There's no chlorine. I checked a few times

 

[CaptainBarnicles]

But did you add water conditioner? Like Prime for example?

 

[Lexiih36]

But did you add water conditioner? Like Prime for example?

I added streets coat, prime, and stability

 

[Oblio]

Assuming you are getting surface flow, you shouldn't have to have an air pump, water circulating should keep oxygen exchange going.

 

[Oblio]

I added streets coat, prime, and stability

I would just use Prime. API Tap Water Conditioner is also good.
Less is more when it comes to chemicals in your tank.

 

[Lexiih36]

The one that was tilted is now struggling to orient itself

 

[Lexiih36]

He's pretty much dead at this point. Completely upside down

 

[CaptainBarnicles]

 

[Lexiih36]

Ok so any ideas, because I'd like to save the last 2 if I can

 

[Oblio]

Did you clean the tank with anything other than fresh water?

 

[Oblio]

Do a 80% water change. Use only Prime to pre-treat

 

[Oblio]

If you have clean treated water, they should thrive (at least for awhile). If your tank is not cycled, we can deal with that.

What test kit are you using?

 

[Lexiih36]

If you have clean treated water, they should thrive (at least for awhile). If your tank is not cycled, we can deal with that.

What test kit are you using?

I have the API master test kit as well as test strips. I've checked all multiple times. No ammonia or nitrites, 15ppm nitrates. Ph is 7.4. I'm fairly certain it cycled.