Is Thrive Killing My Fish?

Discussion in 'Plant Fertilizers' started by tropez, Apr 11, 2018.

  1. tropez

    tropezValued MemberMember

    I have now used Thrive in my tank 4 times now. I have a 29 gallon tank but I only have about 21.3g of water after I subtract subtrate. So I've only been dosing based of 20 gallons of water.

    I've tested my water and I have 0 ammonia, 0 nitrite, 10 nitrate which is pretty steady.

    Out of the the last 4 times I've dosed Thrive, I've had dead fish within the next day or so.

    3/30 @ 5:18pm, did a 14% water changed, added Thrive for the first time, 2.8ml
    3/31 @ 9:04am, had a dead pygmy cory, no visible damage.

    4/3 - Started adding Enhance daily, 2.0 ml per day.

    4/4 @ 8:53am, did a 28% water change, added Thrive for the second time, 2.1ml
    (no dead fish)

    4/7 @ 2:30pm, did a 28% water change, added Thrive for the third time, 2.1ml
    4/8 @ 7:26am, two Golden oto's passed, no visible damage.

    4/11 @ 7:47am, did a 28% water change, added Thrive for the fourth time, 2.1ml
    4/11 @ 1:45pm, noticed a Rasbora struggling to swim at the bottom of the tank, laying on his side or upside down, looking pale. Shortly after that the Betta and Loach started picking at his almost lifeless body and he was a goner.

    So I'm getting worried here. When I test my water, I don't see anything that is of cause for concern. Ammonia is 0, nitrite is 0, and the highest I've ever seen my nitrate was a 10. I usually test as soon as I see a dead fish or a fish struggling. I always treat my water with Prime before It goes in during my water changes and it's always about the same temp as the tank water, 77.

    Could there be something in Thrive that just don't sit well with my fish by chance? I'm really quite scared to keep using the product because 3 out of the 4 times I've used it I seem to have lost fish.

    Last edited: Apr 11, 2018
  2. Buganjimo

    BuganjimoWell Known MemberMember

    I assume you mean the actual volume is around 20 gallons not 2.13? I’d stop using thrive, just as a test. Can you check ph, kh, and gh before and after dosing?
  3. OP

    tropezValued MemberMember

    Correct, that was a typo. I updated the post.

    I can check pH, KH and GH but I haven't been doing so as part of my routine.
  4. OP

    tropezValued MemberMember

    Just tested a bit ago with my APi kit.

    pH: 7.6
    High Range pH: 8.2 (I think, API is hard to read)
    GH: 9 (161.1)
    KH: 6 (107.4)
  5. Buganjimo

    BuganjimoWell Known MemberMember

    Is this before or after dosing thrive? I was just going to see if the parameters changed too much and affected/stressed out the fish.
  6. OP

    tropezValued MemberMember

    After, I didn't test before. Those are the results about 10 hours after the Thrive dosage. Regretfully I don't have pre-Thrive readings right now. :(
  7. Buganjimo

    BuganjimoWell Known MemberMember

    Okay, maybe just stop dosing for a little while. Admittedly, I’ve never used thrive or had any experience with it so I couldn’t tell you what’s wrong. Maybe another member can chime in for me.
  8. -Mak-

    -Mak-Fishlore VIPMember

    The only way to find out is to continue the exact same routine but without Thrive. Currently you don't know if it's Thrive, water changes, Enhance, or an unrelated factor.

    However I think Thrive would be an unlikely culprit. I haven't actually seen anybody with a sure claim that any fertilizer has killed their fish, and there are some people that overdose and EI dose and do all sorts of dosing. Enhance is more likely to kill fish than Thrive, since it's glutaraldehyde like Seachem Excel.
  9. psalm18.2

    psalm18.2Fishlore LegendMember

    Just a note. You should wait 24 hours between adding Prime and Thrive.
  10. OP

    tropezValued MemberMember

    I'm wondering if hitting the tank with 2.0 mL at once during these water changes is causing too much of a spike in something that is harmful to my fish. The 1 x per week dosage of Thrive is 4.26 mL once per week for my 21.3 gallons of water. I had just split that in half, dosing 2.1 mL at each water change to keep things simple, and that was the dosage the first four times I used it.

    I'm thinking of splitting that weekly 4.26 mL dosage across 7 days and just dosing it daily with my Enhance. So that would be a 0.60 mL dosage each day. Just a thought, Colin (NilocG) responded to an email and said that would be fine but he was curious about pH, GH and KH as well.

    FYI, I'm only adding Prime to condition the fresh water, I'm not treating my entire tank. Using about 4-6 drops of Prime per gallon of water.
    Last edited: Apr 12, 2018
  11. -Mak-

    -Mak-Fishlore VIPMember

    Just be sure to change only one variable at a time if you're going to test for it