URGENT! NEWBIE MISTAKE! TRYING TO SAVE MY FISH!

[cloudyskies]

Hi all, I'm sorry for the bold title but I'm in a bit of an emergency with my fish.
The filter of my family's tank broke and my parents decided to install a new filter, as well as replace the majority of water in the tank to clean it (yes, I know, bad idea, but they didn't know).
In reaction to the new water, the fish began to pass away.
Does anyone know if how we could still save the fish, or will time tell?
Our entire family feels guilty, and it's heartbreaking to see them go, so if anyone has any advice it will be greatly appreciated.

 

[fishorama]

Did you save any of the media from the broken filter to put in the new 1? Water changes are always good...in fact I'd suggest large daily WCs until your tank is cycled (again?). Did you remember to use dechlorinator?

Tell us about your tank, everything!! What size & how long have you had set up? What fish & how many? Was the tank cycled before adding fish? What are your tank's water parameters? Ammonia, nitrite & nitrate? There's a sticky at the top of the Newbie forum that explains it if you don't know, you need to understand that.

 

[cloudyskies]

Did you save any of the media from the broken filter to put in the new 1? Water changes are always good...in fact I'd suggest large daily WCs until your tank is cycled (again?). Did you remember to use dechlorinator?

Tell us about your tank, everything!! What size & how long have you had set up? What fish & how many? Was the tank cycled before adding fish? What are your tank's water parameters? Ammonia, nitrite & nitrate? There's a sticky at the top of the Newbie forum that explains it if you don't know, you need to understand that.

We replaced the filter completely and about 85% of the former water (I cringed writing this), and we did put in dechlorinator. We've has the tank set up since february but we bought it from a craigslist ad, so we don't have the instructions despite set up from the owner. The size is 50 gallons.
The fish are guppies, and we had 11, now we only have 5, mostly babies.
We used tap but we ran the filter for 2 hours and put the fish back in, but we removed them once again (again, bad call, but my parents didn't know what to do).

 

[fishorama]

You need to take a water sample to a fish store & have it tested ASAP, I take it you don't have a test kit. You need 1 of your own.

It NOT the water that has caused the trouble, it's the loss of a good chunk of your beneficial bacteria that was in the old filter. 11 guppies should not be a problem in a 50g. Did they come with the tank? I think there's something else going on. Did you add new fish since Feb?

 

[cloudyskies]

You need to take a water sample to a fish store & have it tested ASAP, I take it you don't have a test kit. You need 1 of your own.

It NOT the water that has caused the trouble, it's the loss of a good chunk of your beneficial bacteria that was in the old filter. 11 guppies should not be a problem in a 50g. Did they come with the tank? I think there's something else going on. Did you add new fish since Feb?

Thank you! I will definitely take a sample to a store.
My little sister got the fish as a gift from her friend, so we ended up buying that tank. The fish had babies as we originally started out with 5. But I also have to throw in that my dad cleaned the glass from the inside of the tank with vinegar, which may have played a large part as well.

 

[fishorama]

I don't think you need to blame your dad, unless he used a LOT of vinegar...at the same time the filter died. Then the beneficial bacteria (that are present in the filter media & on all tank surfaces, glass & decor) may have taken a big enough hit to cause all your issues.

I still think there's more happening...we need more info please. But plan to do 50% or more water changes daily & don't forget the dechlor.

 

[dougall]

I know it's late now.. but it could possibly have been the water too. Old tank syndrome is always a possibility in someone else's tanks..

But I would agree that the likelihood is the filter being replaced and the deep cleaning of the tank, not the water.

Probably the best option for the fish would be to temporarily rehome in another tank somewhere until this all has passed, and treat the tank as new and re-cycle it (fishless... read about it)

Otherwise large frequent water changes with dechlorinated water, testing the water just as often (don't necessarily trust a pet store as the likelihood is that they may just tell you it's fine to add new fish). Also think about something that will remove or neutralise ammonia and nitrite for now until the tank has cycled... prime, polyfilter, ammo lock, that sort of thing. use as directed for ammonia issues.