Dying Tetras

[Miss Wiggle]

there's your problem. never ever ever ever ever ever ever ever ever clean your filter media in tap water. you've killed off all or a large chunk of your filter bacteria and the tank is now cycling with fish in. Get a decent liquid test kit to monitor the readings and do water changes every single day until it's passed. You need to prepare yourself for the eventuality that you will loose some more fish.

to speed things up there's a couple of things you can do.

1 - get some mature media from another tank and put it in your filter
2 - get some bio spira/bactinettes which will provide bacteria. However don't just buy any old cycle product, only two of them work, the products mentioned before and they need to be refrigerated. Don't buy anything that's sat on a shelf in an lfs.

 

[JellyPi3]

ok thanks alot for your help
ill monitor the water, and sort out the filter. i have to go to hopsital today for an operation, so not the best of timing, but ill get it sorted. thanks for the advice. i might rehome the fish until the tank is cycled. does that sound like a good idea? my boyfriend has three tanks with fish in, so i might be able to put them in there until its sorted.
thanks

 

[Miss Wiggle]

yes absolutely, if you're not around give your other half the fish (assuming of course his tanks are suitable with no major compatibility issues) for now, then when you're out of hospital get filter media from one of his tanks, add it to yours and you can add your fish back the same day, tank shouldn't cycle like this if you just keep the media in tank water and don't wash it

 

[JellyPi3]

ok then thanks alot, ill get that sorted asap. ill probably stick to the safe side and do a fishless cycle, dont want anymore casualties

 

[Miss Wiggle]

if you like. either way can work.

good luck with the operation, hope your ok