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Anonymous asked in PetsFish · 8 years ago

Why did my goldfish die after one week?

I have a 29 gallon tank. We set it up 2 weeks ago. We filled it with tap water, set up the filter, and conditioned the water 24 hours before we put any fish in it. The next day, we bought a black moor and a goldfish (I'm not sure what kind, but they were in the same tank at petsmart). We put 4 goldfish pellets in every other day. The black moor moved around more, and eventually both started hanging out in a rounded shell on the bottom of the tank. To me, it looked like the black moor was nipping the other fish, and then last Saturday I woke up and the goldfish was just sitting in a plant, dead. I have no idea why. Does anyone have any idea? I did pH and ammonia tests, both seemed normal. Today, I looked at the black moor after we put in a new goldfish, and the black moor has ich. Could this be why the other goldfish died, even though I never saw any white spots on it? And will my black moor die (I started putting rid ich plus (I think that's what it was) in and will continue to do that every day)? And one last question; will the two fish fight each other, because so far I've seen them swim around with each other, and I have seen the black moor dart at the goldfish when it's lying on the bottom of the tank.

5 Answers

  • Nic
    Lv 6
    8 years ago
    Favorite Answer

    1.) You didn't cycle your tank. The goldfish's massive bioload caused a toxic waste build-up of ammonia, nitrate, and nitrite that literally chemically burned your fish, causing it to die a rather painful death. You fail to provide the actual water test results, but ammonia and nitrite should be at zero ppm, nitrate should be pretty low. Ph should be around 7.5.

    Cycling Info:

    *Do 50% water changes to every other day maintain water quality. It will prevent ammonia poisoning while your tank is cycling, saving your other fish. The cycle has started already, so may as well work with it. Buy a water test kit if you haven't already to make sure parameters remain healthy during the process; API makes a wonderful drop kit that's fairly accurate.

    2.) By "conditioned" I hope you mean you dechlorinated the water with water conditioner. If not, you didn't do anything to the tank but let it sit. Assuming this is true, the toxins in the tap water killed your fish. They don't just go away overtime. Unless chemically broken down, they remain in the water. Water conditioner is cheap. There really isn't an excuse for not using it, if you didn't that is. Your question is a bit vague on a few details.

    3.) 29 gallons is only enough for ONE fantail goldfish. They get HUGE and produce tons of waste; they also live 15+ years under optimal conditions, believe it or not. You need at least 20 gallons per fish, period. This rule only applies to fantail varieties. Single tails such as comets and commons get much larger than their fancy fantail cousins and require more space, but let's stick to the breeds you actually own (or in the case of the deceased one, owned). Do *not* add anymore fish to the tank.

    *Side Note: The other fish was probably a common fantail; I notice many chain pet stores house them with black moors.

    4.) Ich rarely kills fish unless the infestation is severe. Goldfish actually have somewhat of a resistance to ich, but when stressed, their slime coat weakens and they can become infected if it's present in the tank. It isn't surprising that the moor got it. Poor water quality = stressed fish. Stressed fish = sick fish.

    With treatment, he should improve if you maintain the tank properly.

    5.) It is fairly unusual for goldfish to fight. They're generally laid back, and don't bother each other aside from playful chasing and nipping. It isn't unheard of though.

    --Please take a look at the care sheet below, and do the proper research before adopting any pet in the future. We've all been where you are, trust me. I started out with a goldfish in a bowl years ago. Needless to say, it didn't last long. Then I made the same mistake with two goldfish in a 10 gallon, who are still alive and doing well in a larger tank, but will likely not reach full size due to stunted growth. They also may have shortened lifespans, but only time will tell. Now that you have the appropriate care information, apply yourself and care for your remaining fish properly. You aren't a bad pet owner, just a human who makes mistakes.

    Best of luck,


    Source(s): Goldfish owner for 7 years and counting.
  • 8 years ago

    Your goldfish produces a MASSIVE bio load that the aquarium could not handle.

    To have healthy fish, you need to establish the nitrogen cycle. It breaks down the ammonia (fish poo) and turns it into something harmless.

    The cycle takes about 6-8 weeks avg. to complete.

    How to start a cycle:

    Fill your tank with water

    Add conditioner

    Add fish flakes/shrimp/ammonia/tetra safe start

    Keep adding a little

    Your cycle should be done in about 6-8 weeks.

    All the work for a fish tank is stressful, but truly worth it.

  • chase
    Lv 4
    8 years ago

    Well let's start with you need to cycle your tank or if you do it with fish be prepared to do a lot more care the next month or so. Ich can be a cause its actually the ich you dont see that's most dangerous (can be in the gills). Your black moor may or may not die ich isn't a death sentence but certainly can lead to death if not treated quickly enough. Your fish should not fight that much right now but your tank is too small to keep both of those fish as adults and may lead to fighting and other problems later in life. Your fish is not drastically below the minimum though assuming its a fancy anyway so it may not be too bad.

  • 8 years ago

    I have found that cycling a new new for a month is better than a conditioning 24hr treatment . It appears that your fish were starving. The links below should be useful.

    Goldfish Feeding

    Common Fish Diseases

    A Guide for Goldfish Care

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  • Anonymous
    8 years ago

    Fish don't always live long. Especially goldfish. Other breeds could last months.

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