2 Tanks, All Fish Dead Within 48 Hrs

Discussion in 'Freshwater Beginners' started by Andrew164, Apr 11, 2019.

  1. Andrew164New MemberMember

    Hello all:

    I have two tanks a 25 gal and 75 gal that i keep in the same room. The 25 gal is the oldest tank and has been established for a while. The 75 gal i have had for about 3 months. I have been traveling on business the last few days and last night I had a call from my wife that all the fish in BOTH tanks were dead. When I left on Monday all fish in both tanks appeared healthy with no signs of disease. i am totally gutted.

    What could have been the cause? I was thinking some sort or airborne chemical poison? Maybe a bacteria or other pathogen ( i did a 25% water change in both tanks about 14day ago using the same siphon for both - could I have spread something that way? death rays from Mars? absolutely no idea what could kill fish in both tanks. at the same time.

    Also what do I do now before starting over?

    Any advice and comments most welcome
  2. Deku-CoryValued MemberMember

    First, I’m sorry for what happened. Loosing fish sucks, especially loosing them all like this. I hope we can find some closure.

    Let’s start off at the basics and go from there. I’d pretty safely cross off any sort of illness being the culprit. Even the most deadly illnesses don’t kill fish all at once, they would be dying over the span of days or weeks.

    What kind of instructions were given as far as feeding the tank while you were gone? It’s possible that they were overfed which caused an ammonia spike, which then killed your fish. It’s a bit unlikely given the short timespan since you left, and again I don’t know the circumstances surrounding feeding, but it’s one of those things that should be eliminated before moving on.

  3. Andrew164New MemberMember


    My wife was giving a pinch of food to each tank in the morning. When she called I had her do a water dipstick test in each tank and look at the ammonia alert disk I have in each tank. ammonia and nitrites we're 0 and nitrate was 20. PH was low around 6.4

  4. Deku-CoryValued MemberMember

    Alright, then that wasn’t it. Good to get that eliminated. You said PH was low, by that do you mean extremely off from normal or just a bit low? If it’s usually like, 7.6 or something than the drastic drop in PH could possibly be the cause, but I’m thinking it’s unlikely.
    I wish I had more to offer, but this is a very strange case. Most of the common culprits are eliminated already. Maybe others will have more suggestions?

  5. FrankieflowazValued MemberMember

    Did electricity go out while asleep? Could be a possibility

    Broken heaters?
    Last edited by a moderator: Apr 12, 2019
  6. Andrew164New MemberMember

    The pH is normally around 6.8. The water here does not seem to have much buffering capacity, and I have noticed that the pH will slowly decease over a couple of weeks, so I do 25 percent water change every 2 weeks.

    Tonight I saw some posts about using crushed coral as a buffer. Will try that when (If?) I start to the tanks again
  7. IslandvicWell Known MemberMember

    Could something have spilled into tanks?


    Anything added to tanks recently? New fish or decor?
  8. JenCWell Known MemberMember

    First, I'm so sorry. That's horrible.

    Did your wife do anything with the tanks while you were gone besides feed them? Does she usually feed them or was it her first time?
  9. toosieFishlore VIPMember

    The pH doesn't sound right for this, but I thought I'd ask it anyhow... do you by chance have planted tanks, operated by the same pressurized CO2 canister?
  10. CandyCane701Well Known MemberMember

    Did your wife possibly spray something in the room?
  11. DuaneVWell Known MemberMember

    I cant imagine it was something airborne to be honest with you. I think that just sounds ridiculous. Killed all the fish in the water, but nobody got sick in the house? Ive used all kinds of things in the same room as my tanks including spray paint, windex, hairspray, etc., and NEVER had a mass die off. A cop buddy of mine told me about a house they were called to that a family died of carbon monoxide poising due to a faulty furnace. He said they had a HUGE tank in the livingroom full of fish freaking out because everyone had been dead a few days and the fish werent getting fed so they were starving. Said it was the weirdest thing.

    Lets be real here for a minute: Does your wife like the fish? No joke, Ive heard of this happening before (happened to my cousin twice before he figured it out). He'd leave town, wife was PO'ed about something and torched his tank. Thousands of dollars of coral, fish, etc., in a 90 gallon marine tank that she poured stuff into.

    Truth be told, I have absolutely no idea how 2 tanks could have a total die off in the matter of a few days. Ive been keeping tanks for over 42 years and Ive NEVER seen that happen. Ive seen a tank have a problem and all the fish die, but it was either a heater shorting out, a filter breaking down, etc. NEVER 2 tanks in the same building at the same time.
  12. JenCWell Known MemberMember

    I admit this was my first thought as well.

    The one thing that came to mind was if the water company did a chemical flush and it coincided with a water change. That's why I had asked if she did anything besides feed them. I think a contamination would have to be pretty severe to take down two tanks immediately.
  13. Meganrae8148Valued MemberMember

    Hello I'd like to say sorry for your loss sure depending on what fish you have if they're more in the intermediate or advance level of fish keep rather then a hardy level fish numeral of things could of killed them all at once and you can cross disease off the list completely perhaps a suddent 3 degree water change ph dropping or rising a cleaning product that could of been used around them fish food that maybe got contaminated but I can guarentee it isnt disease bc they would drop one by one not all at once in both tanks I think you should leave your water rise the tank to 86 to kill any illness u think may of been in the tank add some active carbon to remove anything that may be in the tank that shouldnt like maybe air freshener was sprayed n misked the tanks youd want to remove that keep the carbon running heat up n filter running for the good bacteria feed the nitrates with a source of fish food maybe buy a new fish flaked food in case something spilled on what fish food u were feeding the fish that died or something contaminated the food n then after a month wen you're sure all illness and contamination is gone unless u decided to clean everything thoroughly in the tank in restart the hole fish cycle then u could do that to I'm a beginner so u can correct me if u think I'm wrong but I feel it had to be something major with the water to kill everything at once bc that's the only thing in my sport experience that will even with ick it takes weeks or longer for them to die n sometimes they pull through
  14. Andrew164New MemberMember

    I thought about that and checked the thermometer in the tank it was 72 deg. If we had a long power cut all the clocks in the house would be flashing and they weren't
  15. Annie59Well Known MemberMember

    Tear them down, clean and start over. Something got in both tanks somehow or other. Something not good. That's about the only explanation for 2 tanks to die off at the same time.
  16. Andrew164New MemberMember

    No my wife only fed the fish no water changing or other maintenance.

    She is as devastated as I am about the loss so I don't think she would have done anything as drastic as poisoning the tanks. Although I do have a Nest camera in that room and will go through the recording to see if anything is untoward.

    We do have a couple of cats and my first thought was they had peed on the tanks, but both tanks have glass lids with small cutouts for pumps etc, and there was yellow staining so ruled that out

    My M-I-L was staying and she fed the fish once - could she have had something on her hands?

    no C02 cylinder feeding plants.

    I added new fish and plants to the 75 gal last week (i was just starting to stock it), but nothing new to the 25 gal.

    I opened a new container of fish flakes last week - I keep the lid on when not feeding and there no chemicals near by that would spill into it. Have there been reports of contamination at the factory?

    My only other thought is could the water temp be too high. Both tanks are near (but not in front of) windows. I noticed that they have started to get direct sunlight in the morning for a hour or so. I don't think its long enough to heat the water to high

    I am a beginner at this - I have had the 25 gal about 8 months, and the 75 gal 3 months

    thanks for all the reponses
  17. Magicpenny75Valued MemberMember

    So strange. The only time I've ever been worried about this was with an exterminator - bug bombs or spraying pesticide around the tanks. I had one nasty die off a long time ago, and it was because I had thoughtlessly put my hands in the tank to move something and I had just put lotion on. Everyone died overnight...It was when I had just started out and it was only a 10 gallon. I don't know maybe MIL likes perfumey lotion?? So sorry for your loss. :(
  18. SkavatarWell Known MemberMember

    did you do proper QT of these new fish and plants? probably contaminated both tanks if you used the same equipment for both tanks.

    did she take pictures of the dead fish? any visible lesions, discolorations, etc?
  19. FrankieflowazValued MemberMember

    Update us on what you find in recording
  20. dcocinciValued MemberMember

    I know how you feel....I'm new(er) to the hobby as well. Had this happen to me, 2 tanks at same time. It happened around the same time the city was doing the annual flushing of the hydrants/sewage systems. So only thing we could come up with was something funky with the water source. It happened about 2 days after a water change in both tanks though, not 2 weeks after. I broke them both down, bleached everything then rinsed really well and restarted them again a few months later. One of them has been fine since, the 2nd one completely crashed again for some reason that is still a mystery to me. I've since added sponge filters and MTS to both of them to rule out low oxygen and/or gas buildup in the sand.

    I still jokingly blame my wife and kids for it :)