Fish Dying One At A Time 50 Gallon Tank

Discussion in 'Freshwater Fish Disease' started by Crumpy141, Mar 5, 2018.

  1. Crumpy141New MemberMember

    Hi everyone,

    I am new here so if I have missed anything please do let me know.
    I have a 50 gallon tank set up, it has been set up for some months now. I do 20% water changes every 7 days and my water readings all appear perfectly normal
    The tank is stocked with:
    1 Clown Loach
    2 Pleco
    8 Female Guppies
    8 Female Platies
    1 Male Platy
    6 Cardinal Tetra

    The tank did have 3 male guppies which have now all died and a male Platy which has also died.
    The bit that concerns me is that they have not died together. they have died about 3-4 days apart.
    The tank is planted and sits at around 26 Celsius.

    Does anybody have any ideas if I am doing anything wrong? my only thoughts at the minute is possible bullying between the species which I am missing or something I am not testing for.

    Any help would be greatly appreciated.

    I have only recently started with my aquarium and have had this "hobby" for about 6-8 months in total.
  2. Rojer Ramjet

    Rojer RamjetWell Known MemberMember

    Need specifics on water perameters; ph, gh, kh, additives, TDS, source, decorations, substrate, etc.

    Without that, it just kinda sounds like new tank syndrome.
  3. adh/smile

    adh/smileWell Known MemberMember

    Hello and welcome to Fishlore!

    We are glad to help you but in order to do that, as Rojer Ramjet said, we need more info. Do you know your water parameters? Ammonia, Nitrite, Nitrate, pH, (gh and kh if you can, but I don't record mine and am not sure if it is absolutely necessary to know) tank set up, etc? Could you post a picture of your tank?

    Your fish shouldn't have died due to bullying they are all compatible. You say you've had this "fish hobby for 6-8 months" how long has this tank been set up? Do you know about the nitrogen cycle and what it takes to cycle a tank?

    We'll help you solve your problem! ;)

  4. 86 ssinit

    86 ssinitWell Known MemberMember

    Since it’s planted are you using liquid co2 or excel for your plants? A few months back I had some mystery deaths that happened after co2 doseing.
  5. OP

    Crumpy141New MemberMember

    Hi and thanks for the replies
    I will upload a photo of the test tonight but the last test I did showed

    PH at about 7.6.
    Ammonia at 0
    Nitrite at 0
    Nitrate at about 30 ppm

    I believe the filter has fully cycled. About a month ago I moved the tank to a different location and changed the substrate from gravel to sand but I have a canister filter and made sure that this was kept fresh whilst I changed the substrate.

    I don' think the change is related to the deaths as I had lost 2 or 3 guppies before the substrate change. I also have a sponge filter which was kept wet during the move and everything was cleaned using tank water.
    I was originally using liquid co2 but stopped that several weeks ago once this all started. The only chemicals that go in the tank are api stress coat and zyme.
    Also the very first fish I ever got were the 6 cardinals and they are still perfectly well and happy.

    Last edited: Mar 6, 2018
  6. OP

    Crumpy141New MemberMember

    that photo was pretty small

    Attached Files:

  7. OP

    Crumpy141New MemberMember

    Test 06/03/18

    Attached Files:

  8. Goldiemom

    GoldiemomWell Known MemberMember

    It does sound like your tank is cycled but your nitrates are high. Do a 50 to 75% water change to lower the nitrates. Do you use Prime?
  9. OP

    Crumpy141New MemberMember

    Ill get everything ready for a big water change then. Also no, I don't use Prime, I use Biotopol to de-clorinate water.
  10. adh/smile

    adh/smileWell Known MemberMember

    Nitrates at 30 ppm is really high. You should try and keep it down at 5 or 10. You also don't want to do too huge of a water change because that could throw off your tank's cycle as well. I say 35-50% now and from there to 20-25% every week or two.
  11. Goldiemom

    GoldiemomWell Known MemberMember

    A 50% water change is only going to lower the nitrates to 15 ppm. 35% won't be enough.
  12. adh/smile

    adh/smileWell Known MemberMember

  13. OP

    Crumpy141New MemberMember

    I didn' have everything I needed for a huge change so I did a 30% last night and will do another 30% tonight. Last night though I found another female guppy that had passed away :( could this be something more than high nitrates?

    Could my tank be overstocked considering I did a 30% change on Saturday and by Wednesday my nitrates were this high?

    Is it worth emptying my canister filter and giving it a good clean?

    Is it possible to have "too many" plants?
    Last edited: Mar 8, 2018
  14. adh/smile

    adh/smileWell Known MemberMember

    Plants wouldn't add more nitrites. They help with the cycle of your tank. I think it is just due to high nitrates that your fish are dying. Unless they are sick with something else. Do the fish look normal? Acting normal?
  15. Rojer Ramjet

    Rojer RamjetWell Known MemberMember

    I don't think that 30ppm nitrates will kill most fish; my brackish setups routinely are at 40, and my completely self sustaining desktop 20 (never a water change in 3 years) sits between 20 and 25.
  16. bgclarke

    bgclarkeWell Known MemberMember

    30 ppm nitrates is not high.
    Anything less than 40 is considered to be good.

    All the dying fish are live bearers: do you know what the hardness (GH) of your water is?

    It's also possible that the sponge (s) in your canister may need to be cleaned if it hasn't been done for a few months, but 30 ppm nitrates is fine.
  17. Rojer Ramjet

    Rojer RamjetWell Known MemberMember

  18. OP

    Crumpy141New MemberMember

    Yeah they all look and are acting completely normal

    The water is very hard were we are, could this be a problem with live bearers?
  19. bgclarke

    bgclarkeWell Known MemberMember

    Livebearers prefer harder water, so that's not likely the problem.
  20. Goldiemom

    GoldiemomWell Known MemberMember

    Well, I’m sure we all have the poor thing confused as heck by now with the different opinions. I think for small fish that 30 is too high. Just my opinion though. I am so sorry you lost another fish.

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