Fish suddenly dying less than 2 days after getting them

Hi, I have a 20 gallon tank that has been cycled for about a month, and two days ago I went to a local fish store and bought 6 Cardinal tetras and 3 oto catfish and 3 fancy guppies. In less than 48 hours all the tetras are dead 1 catfish died. i then started adding Brightwell fish recover and aquarium salt but then the male guppy died.

I didn’t quarantine them because I thought because they all came from the same store and they were going to be the first additions to the tank that it wasn’t necessary. I don’t know what to do to next to prevent more deaths from happening. Please help if you can, all advice is appreciated.

 

Water changes. It's always best when setting up newly cycled aquariums to one add a couple of fish in at a time, you probably accidentally added too many at once. The bb couldn't handle that type of bioload (especially with oto cats)

 

Water changes. It's always best when setting up newly cycled aquariums to one add a couple of fish in at a time, you probably accidentally added too many at once. The bb couldn't handle that type of bioload (especially with oto cats)

i thought that too and I tested my ammonia and nitrites and they are both a zero. I believe that there my be some kind of parasite in the water.

 

Sorry for your loss.

How did you acclimate them?

 

Sorry for your loss.

How did you acclimate them?

Thank you.

To acclimate them I let them float in the water for 45 minutes and then did the drip method for an hour before fully putting them in the water.

 

How did you cycle your tank?

did you do a fishless cycle?

what kind of water are you using? well water or municipal?

2 years ago I had major issues and switched to bottled water until I found out it was likely because of chlorine levels due to a poster here telling me that they increase it during summer months ( Southern US state)


I switched to Prime and dosed tank every 48 hours for a few weeks until my tank was cycled. I did 3 water changes a week, later dropped down to 2 water changes a week until 2 months ago with my 38 gallon.

Be careful of dosing salt into the tank as it doesn't leave unless you remove it. I only do salt baths ( add salt to a temporary fish bowl) for that reason if needed due to injury to a fish

I'm sorry you are having these issues, but wish you good luck! My guess would be that the tank really isn't cycled. JMO

 

How did you cycle your tank?

did you do a fishless cycle?

what kind of water are you using? well water or municipal?

2 years ago I had major issues and switched to bottled water until I found out it was likely because of chlorine levels due to a poster here telling me that they increase it during summer months ( Southern US state)


I switched to Prime and dosed tank every 48 hours for a few weeks until my tank was cycled. I did 3 water changes a week, later dropped down to 2 water changes a week until 2 months ago with my 38 gallon.

Be careful of dosing salt into the tank as it doesn't leave unless you remove it. I only do salt baths ( add salt to a temporary fish bowl) for that reason if needed due to injury to a fish

I'm sorry you are having these issues, but wish you good luck! My guess would be that the tank really isn't cycled. JMO

I did A fishless cycle with ammonia and bottled bacteria.

I use municipal water with fritz complete as the conditioner. Even though I have been considering using prime.

I think my tank is cycled, because every time I dosed the tank to 2ppm ammonia it would be back to zero in less than 24 hours, and even when the ammonia spiked to .25 ppm with all the dead fish it went back to 0 in a few hours.

 

Could also just be bad stock. I know otos are often wild caught and guppies are so inbred that they can be unhealthy

 

Oto cats are infamous for being very sensitive. They need a tank that is very seasoned and do better if it is set up for at least 6 months and even then they are iffy. Many types of tetras (especially neons and cardinals) are also sensitive and prefer the seasoned tank. Keep testing the water because adding more than 2-3 fish at a time is alot for the BB in the tank. Water changes are your best friend.