Fish Dying Without Warning 75 Gallon Tank

  1. Fishlover832

    Fishlover832 Valued Member Member

    I know I've posted multiple threads in the past about this, but I still haven't figured it out. Today I had another fish die with no warning. The only signs I've sometimes noticed is lack of appetite and loss of color. This time, just found a hatchetfish stuck to the filter. Keep in mind I started with 7 of these in qt for 3 weeks. After this death I'm down to only 1. At the same time I bought the hatchefish I also bought 6 cardinal tetras and 7 African dwarf frogs. Over the course of 2 weeks, all the cardinal tetras died and all of the African dwarf frogs lived (both were in a cycled and planted 20 gallon long). African dwarf frogs were well fed and didn't show signs of aggression. Within the past few days I've noticed another rummynose tetra losing color, appetite, and size. Let me rephrase a lack of appetite to rather just that they can't swallow the food. What the heck do I do? I tested my pH and found it was about 8.2. Nitrates around 5, ammonia and nitrite at zero. I work an internship with a local university for chemistry research so maybe I could ask them to inspect my dead fish for diseases. Other than that I'm completely lost and I really want to give up and just do something like a flowerhorn lol.
     
  2. bitseriously

    bitseriously Well Known Member Member

    Can u give a couple key pcs of info, for those of us who haven’t seen your other posts?
    Tank size?
    Inhabitants?
    Thx!
     
  3. OP
    OP
    Fishlover832

    Fishlover832 Valued Member Member

    Sure no problem. I have a 75 gallon planted tank with cardinal, rummynose, and serpae tetras. There are some habrosus cories and sterbai cories, otocinclus, and a red lizard whiptail pleco (L010A). I have a planted 20 gallon long with 7 African dwarf frogs and a 5 and 10 gallon qt tank. I just took out the dead hatchetfish and noticed his belly was pretty enlarged. This could be due to the fact that he gets to the food first because he's at the top, but I'm not sure.
     
  4. Sarah73

    Sarah73 Fishlore VIP Member

    Ok so it sounds like you over stocked the tanks before the filters could catch up. Only add 5 fish at a time, wait a week then add more. What's your temp?
     
  5. OP
    OP
    Fishlover832

    Fishlover832 Valued Member Member

    Temperature is usually around 78 but with hot days it can reach 81. Also, the main problem is in an established 75 gallon tank. Regardless of the cardinal tetras dying in the 20 gallon long, I'm having multiple deaths randomly in the 75 gallon. Right now I have a serpae tetra that might be starting to lose color, plus a rummynose that keeps spitting out food and is therefore getting skinny. Everyone else looks happy and healthy.
     
  6. Sarah73

    Sarah73 Fishlore VIP Member

    What are you feeding them? I need to go to bed, so I'll contiune tomorrow.
     
  7. OP
    OP
    Fishlover832

    Fishlover832 Valued Member Member

    I feed fluval bug bites and omega one flakes. I feed omega one algae wafers for the bottom feeders plus an occasional cucumber piece. On the days that I feed bloodworms to the frogs, the fish get some too.
     
  8. bitseriously

    bitseriously Well Known Member Member

    So let’s just focus on one tank at a time. It sounds like your 75 is the problem child. You listed a lot of fish types, but what kind of numbers are you keeping (how many of each)?
     
  9. OP
    OP
    Fishlover832

    Fishlover832 Valued Member Member

    Since my lights aren't on yet I can't double check numbers but here's a rough estimate:
    6 cardinal tetras
    6 serpae tetras
    8 rummynose tetras
    4 otocinclus
    1 hatchetfish
    4 salt and pepper cories
    7 sterbai cories
    1 red lizard whiptail pleco
     
  10. bitseriously

    bitseriously Well Known Member Member

    @Fishlover832 I keep reading and re-reading your original post at the top, and can't figure out the timeline here. Maybe others are in the same boat?
    Can you confirm/clarify, or at least correct me if I'm wrong:
    - are all the fish in the list above in a single tank at this time (75gallon)
    - how many of them have been recently added?
    - how long was the tank running/stable prior to that?
    - presumably you moved the school of hatchets from the quarantine to the 75 recently, but the hatchets have all (or all but one) died since the move?
    - are you continuing to see intermittent/gradual losses in this 75 gallon tank?
    - did the cardinals from the quarantine tank die while in quarantine? And then you moved the hatchets from the same quarantine into the 75? How long after cards died?

    The thing I keep thinking about is 'community instability'. With that many schools and individual fish in your tank (and I'm not suggesting you're overstocked, but would like to know what the 'stocking gurus' think), any change in the setup (adding new fish) is likely to cause some level of disturbance to whatever happy order existed previously. Disturbance = stress. Stress = opportunistic pathogen. Opportunistic pathogen kills vulnerable fish. It's something I've been through personally over the past year. Through a series of losses, I've finally reached a setup that has been stable for a couple months, with zero losses .*knocks on wood*
    I know it's frustrating when fish keep dying and no amount of water changes, medication etc seems to stop it.
    I also know that folks tend to look for that silver bullet, something they can fix that will stop the losses. But often there isn't one problem, there are many. Prioritizing and nailing each one down (especially when you don't even know what they are) can be hard. So you're left with doing what you can, to provide the best possible conditions and the least amount of stress/disturbance until things stabilize.
    Any of this sounding like it might be what's going on in your case?

    P.S. LOVE the red lizard - haven't seen that before and now I wants it!!
     
  11. OP
    OP
    Fishlover832

    Fishlover832 Valued Member Member

    All of those fish have been established (despite there being intermittent losses) in the 75 gallon tank for a few months. The only ones added recently were the 7 hatchetfish. All 6 of them died in the 75 gallon tank after about 3 weeks of qt. I am continuing to see gradual losses in the 75 gallon. The cardinal tetras came from a separate qt tank. They were in a 20 gallon with some African dwarf frogs. I do believe I put too many fish in that tank too quickly, but I'm still shocked that none of the african dwarf frogs died or showed signs of stress.