Dying fish

[Anna94]

I bought new fish a few days ago and the next morning I went to feed them and I accidentally dumped a whole bunch of food into the tank. So I immediately tried to net some of it out and I did but I also did a 50% water change and gravel vac and took the filter apart, rinsed the filter media in tank water, and took the plants out cause they needed to be soaked anyway due to diatoms. I sucked up as much food as I could. I put the filter back together and refilled the tank and dosed Prime and Stability, but a few hours later as I had to go to the store and buy it. The next morning I found 4 dead fish, all of them were from the new batch of fish. I tested my water and nitrites and ammonia were 0 and nitrates were between 10 and 20. I did another 50% water change, mostly to clear out some green algae that I had scraped off the glass and to suck up more food, and dosed with Prime and Stability again. This morning I went to go feed my fish and found 4 more dead fish. This time they were from my old batch of fish. I tested my water again and got the same results. This time, though, I tested the PH and it was between 7 and 8. I’m afraid I’m going to find more dead fish tomorrow or later today. My old fish were all doing fine until now.

 

[Angelfish owner]

You might have killed off alot of your bacteria

 

[gilpi]

You rinsed the filter in tank water, you did the right thing, how much you rinsed it could have been part of the problem, I would not bet on it though. Perhaps the big water change also might have been part or all of the problem since it was a big change for the fish environment... water conditioner with the water change? Temp change?

For years I used to change half to three quarters of the tank's water in my African cichlid tank, since the water was always high pH and hard, fish were happy until one day there was an issue with the water supply and the pH totally dropped killing half my stock.
There's a few things that could have gone wrong here. What is your tank's size?

 

[Anna94]

You rinsed the filter in tank water, you did the right thing, how much you rinsed it could have been part of the problem, I would not bet on it though. Perhaps the big water change also might have been part or all of the problem since it was a big change for the fish environment... water conditioner with the water change? Temp change?

For years I used to change half to three quarters of the tank's water in my African cichlid tank, since the water was always high pH and hard, fish were happy until one day there was an issue with the water supply and the pH totally dropped killing half my stock.
There's a few things that could have gone wrong here. What is your tank's size?

I used Prime water conditioner and the water temp didn’t change as far as I know. The tank is a 29g tall. I found 2 more dead fish this morning.

 

[gilpi]

Sorry you kept losing fish. The new fish you bought, is it still alive? Could you let us know what type of fish you have and how many?

 

[Anna94]

Sorry you kept losing fish. The new fish you bought, is it still alive? Could you let us know what type of fish you have and how many?

I’m down to 3 fish now: 2 guppies and a black neon tetra. The ones that died were cardinal tetras, lemon tetras, and black neon tetras. Some of my fish that died I’ve had for 2 years.

 

[Aiken Drum]

Is there any sign of illness in the fish?

Could you check your water parameters again.

Is there any chance you forgot to add water conditioner when doing a water change?

 

[Anna94]

Is there any sign of illness in the fish?

Could you check your water parameters again.

Is there any chance you forgot to add water conditioner when doing a water change?

No, I didn’t forget to add it when refilling the tank, but I did forget to add it to the water I was using to refill the hob filter. One guppy looks a little fat, but he ate just fine as did the other 2 fish and he could have been fat since I got him and I’m just now noticing. I can’t check my water parameters until tomorrow as I did a water change today and dosed with Fertz water conditioner so I don’t want it showing me a false positive.