My Fish Keep Dying. 90 Gallon Tank

Discussion in 'Freshwater Fish Disease' started by flamesfan*09, Mar 21, 2010.

  1. flamesfan*09New MemberMember

    Hi, I hope someone can help me. I have a 90 gallon tank and it has been up and running for about 1 1/2 months now. I had a little spurt of my ammonia and nitrate and nitrites going up and now everything has returned to 0 .. It has been at 0 for about a week now and I have recently added 10 new fish into my tank. For the past couple days I have lost 6 fish and my testing kits are still at 0 for all the stages (ammonia, nitrate, nitrites) . I am wondering why my fish are dying.

    The kinds of fish I have are; barbs, guppies, angels, tetra's, mollies, platties.
    I also have a few Cory's for a bottom eater.

  2. BennyBValued MemberMember

    What is the temperature of the water? What is the pH? What is the salinity? Have you added any chemicals to the water recently? What kind of filter media do you use? Do the fish look sick at all?(White spots, cloudy eyes, ripped fins, red or bloody looking gills, etc.?)

    Sorry for asking so many questions, but there are a lot of variables. :)

  3. bassbonedivaFishlore VIPMember

    Nitrates should never be at zero unless your tank is brand new. Ideal tank parameters are:

    Nitrates indicate the good bacteria which help keep ammonia and nitrite levels at 0.

    It really sounds like your tank isn't fully-cycled yet. When did you add your first fish?

    Also, all the fish you have like warmer temperatures, closer to 78-80F. Lower temperatures will make your fish much less active and make them more susceptible to diseases.
  4. MeenuFishlore VIPMember

    Welcome to FL, Katie.
    I agree with Paige, your tank is cycling. You should see a spike in the ammonia first, and then, as ammonia goes down, you'll see nitrites. Both of these are dangerous for your fish. As the nitrites go down, you will see a rise in nitrates, and once you have 0 ammonia, 0 nitrites, and some nitrates, you are cycled. My tank is usually 0,0, 5, which is really good.

    If you have live plants, it is possible that your tank is cycled. Plants "eat" nitrates, so it is possible to have 0,0,0. Do you have live plants?
  5. BennyBValued MemberMember

    But be sure you consider what I asked also. Don't forget the possibility of your fish just being sick.

    This is what happens in my betta's tank. I have so many plants in there, there are never any nitrates.
    Last edited: Mar 21, 2010
  6. gef21Valued MemberMember

    how did you acclimate your fish?

    How soon after you put them in did they die?

    What numbers of those fish do you have?
  7. flyin-loweWell Known MemberMember

    You said you ran the tank for a month and half and recently added ten fish. Before you added these ten fish was there anything in the tank? A month and a half is average time for a tank to cycle if there is a bacteria source (fish, or ammonia etc.). If the tank just sat running for a month and a half with no ammonia source then it is not cycled.
    That said if you tested your water after your fish started dieing and you still had no ammonia or nitrites that wouldn't be what killed them.
    Also let us know which of the fish died.
    You said you have
    "The kinds of fish I have are; barbs, guppies, angels, tetra's, mollies, platties.
    I also have a few Cory's for a bottom eater."

    If the angels died this could very well be because they need to go into a tank that is established, not brand new. Depending on what kind of barbs you have they could have killed the guppies. Let us know what has been in the tank and how long it has been there, and also which fish died.
  8. Craig-DValued MemberMember

    I agree with the others above. If you have no nitrates, your tank is not cycled and that's a sure fish killer. The fact that you keep your tank at 70 degrees isn't helping matters. All those tropical fish in your tank require the mid 70s at least. aise the temp to at least 76 and go grab yourself some Tetra Safestart to cycle that tank in days if you have no way to relocate the fish. Get some Amquel+ to remove all toxins while your get this tank cycled. Also you make sure you treat any new water to remove chlorine.
  9. michael68Valued MemberMember

    I agree that since you have a o nitrate reading that your tank hasnt even begun to cycle.What did you use to treat the water you put in the tank?Also fish can die from incorrect ph if not aclimated correctly.Certain fish can deal with a different ph that they are used to if aclimated correctly.

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