Oscar Died. What did I do Wrong?

[Zak03]

Alright. So I purchased two baby Oscars (red and tiger) from Petco a little bit over a week ago. They live in a 40-gallon tank ( i will upgrade later, don't worry) with two baby sun catfish and two baby common plecos (which I added today). I apologize in advance for the amount of reading you guys will have to do, but I don't know what info I need to include and what I don't, so imma just add a lot of info.

My tank is not fully cycled, but I don't think that's why my Tiger Oscar died. Before two days ago, I only had my two Oscars and the catfish in the tank. Then, two days ago, I added the second baby sun cat to keep the first one company. as soon as I released the cat into the tank, the two Oscars began to harass it. so I removed them and put them into a quarantine tank. after about 40 minutes, I put the Oscars back into their original tank. They didn't harass the new cat anymore. but they got really moody. like really sad; they sulked. so I did some research.

I read here on MFK that Oscars can get moody/sad when they're moved from tanks, tank decor is rearranged, etc. so I figured they'd be okay the next day. yesterday I woke up, and my red oscar was swimming throughout the tank, but the tiger oscar wasn't. I figured to give him some time. later on, I tried to feed my Oscars. (note: I have been having feeding problems, finding the correct food they like. I figured out that they liked sinking pellets, but I had floating pellets. so I bought some when I purchased my second cat). And the Red Oscar finally ate. The Tiger Oscar didn't eat cause he was hiding this whole time.

This went on the whole day. He barely moved all day. I figured he would be back to normal the next day (today). When I went to bed, I turned off the lights and turned on the moonlights. After some time, the Tiger Oscar eventually came out and moved about just a bit. but not much. This morning, I woke up to my Tiger Oscar laying on the tank floor. Dead. So I went and bought a replacement Oscar and the two plecos.

So my question is, why did it die? My other fish, Red Oscar and one of the Sun Cats, have been in the tank just as long and a bit longer respectively. But they're in great shape. What caused it to die? I want to know what to do make sure the rest of my fish don't die.

 

[Rhyno8]

My bet would be on uncycled tank coupled with the stress of moving from tank to tank. If your tanks not fully cycled you really shouldn’t be adding more and more fish. Have you tested parameters? Uncycled the ammonia or nitrite could very well have spiked.

 

[dan518]

As said above, uncycled tank, stress of new fish added, stress of being moved. I would test the water parameters before you lose the rest.

 

[duanes]

Agree with the 2 posts above, an un-cycled tank would be the most logical conclusion, and then to top to off you added another fish, increasing the toxic ammonia production by 25%. Do not add anymore fish for at least another 6 weeks, when if the cats are still alive the tank will probably be cycled.

 

[Andy woods cichlids uk]

Yes agree with the above. The adding new fish to a tank not fully cycled is a BIG NO NO.

 

[Rhyno8]

Advice for the other fish would be daily water changes to bring down ammonia levels add prime to bind the ammonia and some aquarium salts to help negate the effects of nitrite.

 

[tlindsey]

All statements made are accurate. Sorry for the loss of your fish.

 

[EntoStentor]

I agree with the posts above, but if one oscar died and the other didn't, could it have been a diesease? Petco is one of the worst pet stores (they abuse their reptiles and keep fish in horrible conditions, they'll sell you a 4-inch common pleco and tell you it's full grown etc.) and the numerous tank changes coupled with an uncycled tank and the bad conditions they would have been in at petco probably contributed to the demise of that unfortunate one. Also if the tank isn't cycled properly, you should expect the dying one to be swimming a lot, but it was staying still. Did you check for ich, fin rot, worms etc. Did you check the pH? Did you acclimate them before adding them to the tanks? Water hardness? Nitrogen compound level? All of these questions need to be answered for me to get a good idea of what actually went on.

 

[tlindsey]

I agree with the posts above, but if one oscar died and the other didn't, could it have been a diesease? Petco is one of the worst pet stores (they abuse their reptiles and keep fish in horrible conditions, they'll sell you a 4-inch common pleco and tell you it's full grown etc.) and the numerous tank changes coupled with an uncycled tank and the bad conditions they would have been in at petco probably contributed to the demise of that unfortunate one. Also if the tank isn't cycled properly, you should expect the dying one to be swimming a lot, but it was staying still. Did you check for ich, fin rot, worms etc. Did you check the pH? Did you acclimate them before adding them to the tanks? Water hardness? Nitrogen compound level? All of these questions need to be answered for me to get a good idea of what actually went on.

Yes very well a possibility but ammonia or and nitrite levels spiked do to the addition of the bioload of a uncompleted cycled aquarium. Even after aquarium fully cycle's you must still be cautious.

 

[EntoStentor]

It was just that one oscar that died tho...

Correct me if I'm wrong, but doesn't everything in the tank exhibit symptoms if there's a spike?