Large Die-Off after water change

[Jan Cavalieri]

Each week I pay a friend of mine to help me do a 75% water change for each of my tanks. We do that large of one because 1. I tend to overfeed and 2. Some are big pooping species - like pleco's. Yesterday we changed the water on a tank - when we were cleaning up we noticed that a little Killifish had died. Later after my friend left - I also found that both my Thomasii's died (plecos) and one of my Peppered Cory Cats died. I can't find the other Killifish but I've found a Gourami alive and so far - at least one of my two Bristlenose Plecos (I have 2 and both are good at hiding considering they are yellow) and one of my catfish - but I may still find I've lost more after I take some of the plants and decorations out.

Any idea what we could have done? We know we added Prime to the new water and that's the only chemical that got added. My concern when I found the first one was that the water was awfully warm - and looked on my chart and found that all the fish that died prefer water in the mid-70's - this tank is usually at 80 because the d*mn thermometer will only adjust to 70, 80 or 85 and ignores any other adjustment you try. This water was closer to 84 degrees by my estimate. Would this kill off a bunch of fish all at once? I should have checked her water temperature but she's been doing it a while but each aquarium has it's issues and she may have forgot to check the new water before she put it in.

Current readings are:
Ammonia: .15
Nitrites: .10
Ntrates 0
PH: 7.12
Temp: 80 F

So I did add a chemical that neutralizes ammonia and nitrites (actually even just prime will do this for a couple of days). Today I'm going to switch out some of the water as well and see if I find any more fish. I'll be changing it with slightly COOLER water to say the least.

Any other ideas as to what killed them I really loved my Thomasii's - they look so much like real people (actually zombie people) and they were getting so friendly.

 

[Metalhead88]

Are those readings after the water change? If so, water quality was even worse before it. Why are nitrite and ammonia so high?

These fish are heavily stressed in this water quality. Water changes can be stressful and if these fish are already weak, it could put them over the edge.

A heavy change in temperature can do it as well. Do you have a thermometer? Temperature should be monitored as the tank fills.

 

[utahfish]

80s is pretty high temp but if the added water was same temp then it shouldnt cause any shock. If it was cooler or warmer then yeah could kill fish.
Having said that if you are getting nitrite and ammonia then your tank isnt cycled.
If ones tank has been running for a while then somehow your biological filter is being killed.
Majority of beneficial bacteria will be in filter media. If one is changing the filter pad and replacing with new one the loss of beneficial bacteria on the discarded filter pad can cause an ammonia spike killing fish.

 

[Colin_T]

Something in the tap water poisoned them.

Water companies have been increasing chlorine and chloramine levels due to covid19 and that might have happened with your water supply.

A change in temperature will not cause massive fish kills unless there is a major change of 10 degrees or more.

Check the tap water for ammonia, nitrite, nitrate and pH and make sure it is safe.

A sudden change on pH could kill them.

 

[utahfish]

Also wouldnt add any ammonia or nitrate regulators. Like ammo stop or ammo chips. They claim to denitrify ammonia into a non toxic form which would be nitrate in doing so this starves the biological filter from the nitrifying bacteria it needs to function. When ones biological filter is out of whack one can have ammonia spikes because the beneficial bacteria isnt being broken down.

 

[Jan Cavalieri]

It IS something in the water and I don't think it's hot water - for one I just found one of my bristlenose pleco's dead (it's the one I couldn't find) - I found her after removing 4 buckets of water. For a test, I decided to test the water in the other tank we did a water change on yesterday and guess what - it also tested a .15 in ammonia getting ready to test my tap water now. This tank however, I'm not seeing anything dead so far.

The other thing I did was accidentally leave a piece of Romaine lettuce in there for 3 days - it was obviously decaying - limp as a rag so I can see where that might have caused it. I'll test another tank we didn't change out yesterday but still has the Romaine lettuce in it. Boy I just feel sick.

 

[Jan Cavalieri]

Ok - here are the results - test of water with nothing but Prime in it: was Ammonia zero (this was my tap water)
Test from Tank that DIDN'T get a water change yesterday - but did have Romaine lettuce for at least part of yesterday was - Ammonia - ZERO. I forgot yesterday while I was waiting for her I pulled the Romaine lettuce out of one tank.

So greatly relieved it wasn't my tap water - that would have been an impossible situation - I'd just save as many as I could and retire from the fishing field (I probably should anyway since I can't do it all myself).

I'll ask her but I wonder if she forgot to put in the Prime? But even then I'd think we'd have enough in the water with a 75% water change because we tend to put in a capful a bucket when I've heard you just need a few drops - so we would have about 5 gallons of water in there with prime but 24 gallons without - so yeah I guess that could be the source.

At least I only have to replace the water in 2 tank tonight - I can't get ahold of her - last time I did it I had a minor heart attack so I was told not to do it any more - so I'll try 1/2 a bucketful at a time. It's going to be a long night. But why no deaths in the other aquarium with a huge assortment of fish - while it took out almost ALL my fish in the tank with few fish in it. So far my Blue dragon is still alive - super expensive. But I'm going to cry over losing my other Pleco's they were so cool and so sweet.

Somehow I still think it was that rotting lettuce - has anybody else had an ammonia spike from rotting vegetables?

 

[JuiceBox52]

Ok - here are the results - test of water with nothing but Prime in it: was Ammonia zero (this was my tap water)
Test from Tank that DIDN'T get a water change yesterday - but did have Romaine lettuce for at least part of yesterday was - Ammonia - ZERO. I forgot yesterday while I was waiting for her I pulled the Romaine lettuce out of one tank.

So greatly relieved it wasn't my tap water - that would have been an impossible situation - I'd just save as many as I could and retire from the fishing field (I probably should anyway since I can't do it all myself).

I'll ask her but I wonder if she forgot to put in the Prime? But even then I'd think we'd have enough in the water with a 75% water change because we tend to put in a capful a bucket when I've heard you just need a few drops - so we would have about 5 gallons of water in there with prime but 24 gallons without - so yeah I guess that could be the source.

At least I only have to replace the water in 2 tank tonight - I can't get ahold of her - last time I did it I had a minor heart attack so I was told not to do it any more - so I'll try 1/2 a bucketful at a time. It's going to be a long night. But why no deaths in the other aquarium with a huge assortment of fish - while it took out almost ALL my fish in the tank with few fish in it. So far my Blue dragon is still alive - super expensive. But I'm going to cry over losing my other Pleco's they were so cool and so sweet.

Somehow I still think it was that rotting lettuce - has anybody else had an ammonia spike from rotting vegetables?

Is there anyone else you could ask to help you do it?

 

[Jan Cavalieri]

Oh and I tested all my tanks about a week and a half ago - all had perfect numbers, even nitrates which is unusual for me since I have one tank that is continuously dirty - must be algae.

 

[Jan Cavalieri]

Only other person in my life is my daughter and shes 8 months pregnant and restricted from seeing anybody except her husband, until she has the baby. Luckily they both work from home in the IT field and she's been told she is not to go into the office no matter what - she has a good employer.

 

[Retired Viking]

I do not know if this will help but when it is warm out I use a garden hose to drain my tanks out a near by window and fill a large plastic container by the tank using the same hose. I then add a couple of buckets of hot water to warm it up. Saves on carrying all those buckets.

 

[Jan Cavalieri]

I'll talk to my friend - she's suggested a lot of different thing - that being one of them. I have Python too she wants to try - for me it was a mess because it kept getting wound up in my oxygen hose - a problem she wouldn't have - that's a very fast way to move a lot of water too but draining it is a pain in the butt. Water gets trapped between the two ends of the hose and you have to play with it until it decides to come out LOL. Besides being disabled I'm also short and small and it's an 80 ft hose - and I've sucked curious fish up it a couple of times too. Moving tanks and buckets of water just too much for me - I started this after my precious Bassett Hound died of cancer - I wasn't able to walk her any more either so she became overweight and diabetic. Thought fish would be less work and I wouldn't get as attached to them. That's not working out. I have 5 fish left in that aquarium that used to have 12 fish. I was just getting ready to buy some more fish since at one time I had 25 of varying sizes and personalities. I don't know why these 4 lived and all of them lived in the other tank with the same ammonia level - one is an evil little danio that once killed off all his school mates and then ate the fins off a gourami and I had to euthanize the gourami (should have euthanized the danio but he hasn't killed anything since). . One of the Gourami's isn't looking very good but now that the water change is done I hope he will be fine.

I took an ammonia reading after removing 4 buckets of water and the ammonia level isn't quite zero but also isn't quite .25 either - just in the middle so good enough. Fish live though that all the time. I can stop worrying now I think.

 

[Colin_T]

Somehow I still think it was that rotting lettuce - has anybody else had an ammonia spike from rotting vegetables?

Rotting plant matter can cause ammonia spikes but a healthy filter should remove any that is produced unless you have lots of rotting plant matter. One lettuce leaf in a 3 foot tank is unlikely to be a problem.

Is it possible something else was introduced into the tank when the water change was done?
eg: something on your friend's hands/ arms that contaminated the tank?

Did you rinse the lettuce leaves before putting in the tank?
I doubt it was the lettuce but there might have been something on them, although I would have thought that would cause problems straight after you added it to the tank.

 

[Jan Cavalieri]

I did rinse the lettuce before putting it in the tank. I cannot figure out what we did that was any different than any other time we've done. If fact (TMI) she went to the restroom and came out and said "I made sure to get the soap off my hands before working with the fish and laughed because I'm always reminding people (kids mainly) about not putting their hands in the tank or anything else because it could poison or stress the fish. The wimpy lettuce leaf just looked so decayed that's why I thought of it. Plus the floating plants in both the tanks isn't in great shape but it's actually worse in the tank where there were no deaths

 

[Jan Cavalieri]

Amd maybe it wasn't ammonia that killed them since it was just as high in the other tank and didn't kill any fish - in this tank it killed 7 out of 12