ALL FISH DEAD IN ONE NIGHT... HELP

KelberiFishLover19

Jack Dempsey
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Aug 10, 2018
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He guys so about a month and a half ago I set up a 55 gallon tank for a good friend of mine. I had a high budget so I decided I was going to make it a super nice tank. His only suggestion was that he wanted sand. Everything else was up to me. So I got some stone hinge and a nice Fluval FX4 canister filter. I cleaned up the rocks and let the tank run for a month or so. I’m super careful with my fish and especially when they aren’t mine so before I put them in, I checked everything to make sure it was alright. I got him 4 OB peacocks and a royal pleco. I did a water change once a week. Water was never bad, temperature was 80, and the fish were eating. Everything was fine. Then one morning 3 weeks later, all of the fish were dead. I am experienced in the fish keeping hobby and I’m stumped. I just cannot figure out how this happened. The night before they all were fine, all ate. I have talked to a few close friends of mine who are also into fish keeping and they just can’t figure it out either. I want some opinions on what you guys think happened because this is just bizarre.
 

Gourami Swami

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Do you test your water? what are the parameters like (pH, ammonia, nitrite, nitrate) ? was the nitrogen cycle completed before adding the fish, if so what method was used? Have you checked for any equipment malfunctions? What is source water, and if tap, check with city for any irregularities?
 

kno4te

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Sounds like a not cycled tank and bad water quality kicked in.
 

KelberiFishLover19

Jack Dempsey
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Aug 10, 2018
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Ph was 7.8 nitrate/nitrite were at 0. Ammonia was at 0 as well. Nitrogen cycle was completed. I let it go for a month and tested the water once a week. The water was fine when I put the fish in and when they died. Equipment worked properly. Water stayed at a constant 80 degrees and the filter is a 250$ filter that has multiple layers of filtration. Water is city water but I checked that water before I used it and everything was fine as well.
 

Troy1015

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Ph was 7.8 nitrate/nitrite were at 0. Ammonia was at 0 as well. Nitrogen cycle was completed. I let it go for a month and tested the water once a week. The water was fine when I put the fish in and when they died. Equipment worked properly. Water stayed at a constant 80 degrees and the filter is a 250$ filter that has multiple layers of filtration. Water is city water but I checked that water before I used it and everything was fine as well.
No way a 55 gallons had 0 nitrate impossible. Either you didnt test or your test failed.
 

jwitty

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Dec 27, 2018
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Not a fully cycled tank if there is no nitrates. Few exceptions but really should have at least some nitrates.
 
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KelberiFishLover19

Jack Dempsey
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Aug 10, 2018
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No way a 55 gallons had 0 nitrate impossible. Either you didnt test or your test failed.
The nitrate was around 0. Even if it wasn’t 0 and it was close it shouldn’t have killed all of the fish in one night and it happened after 3 weeks of the fish being in the tank. A big change like that doesn’t happen over night.
 

jwitty

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It wasn’t exactly 0 I was just saying that it wasn’t like super high.
Well typically most like to see around 20ppm of nitrate. 6-8 weeks is what typically takes for a fully cycled tank. Not a month. At least that’s what it is for me and many others.
 
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