Tank crash while on vacation.... What was it?

[Ryan S.]

Hello all,

Looking for some help identifying what may have gone wrong.  Just got back from vacation and one of my larger tanks lost almost everything.  Here are the details.

Lost 2 electric blue acaras, two panda Garra, 6 bosemani rainbow fish and two bristlenose plecos.  Surviving were 5 of 6 corydoras.

I was gone a full week.  Fish looked like they had been dead for awhile, at least 24 hours.  Only food was 2 nano banquet ball things. Tank is heavily planted with floaters (broad leaf water Sprite) and is seasoned.

Tank parameters were solid. No ammonia, nitrite, low nitrate. No ph crash. I found this to be the most perplexing part as this test was done while fish were still in the water. Temp was 76 degrees normal.  All other tanks on the rack were fine with no casualties using the same banquet feeding things. 

I doubt if my cycle crashed it would have recovered already? Could have been a sick fish I guess or the banquet ball thing.... I'm at a loss. Any thoughts?

[Flumpweesel]

I lost my entire tank due to a vacation mystery, my best guess for my scenario is that one of the bigger fish died and because no one was there to remove it the rest of the tank struggled as the decay process used all the oxygen. The only fish that survived were the corys presumably because they can do the intestinal breathing thing when things get nasty. 

How much food had gone could something have tried to eat there lot?

[Ryan S.]

On 11/28/2021 at 5:40 PM, Flumpweesel said:

I lost my entire tank due to a vacation mystery, my best guess for my scenario is that one of the bigger fish died and because no one was there to remove it the rest of the tank struggled as the decay process used all the oxygen. The only fish that survived were the corys presumably because they can do the intestinal breathing thing when things get nasty. 

How much food had gone could something have tried to eat there lot?

Yeah I could see a similar scenario. Only thing that makes sense. Thanks for the input!  Just a bummer. 

[Flumpweesel]

On 11/29/2021 at 1:36 AM, Ryan S. said:

Just a bummer. 

Yup, still hurts. 

[Brandon p]

I have had this happen before. In the end for me the person trusted to feed them never feed them. The tank was well planted not all fish died but the ones I would have expected to live died. 3 sliver dollar and a few others but the siliver dollars eat mostly plants in the wild. I have a theory that the change  in feeding affects how the fish survive. We have seen videos of Cory and Dean prepared there ways they feed when they are gone. I’m sorry to hear about your fish.

[gardenman]

When I've had tanks crash it's typically because a fish died and was out of sight. Things can spiral out of control pretty quickly when that happens.

[Brandon p]

Why is it when people leave does that first fish die that causes the rest to die

[PineSong]

First of all, what a sad find at the end of a vacation--I'm sorry this happened for you.

What kind of filtration/aeration was on that tank, and was it the same as the other tanks? Just wondering if there was a power outage or something while you were gone, that this tank did not recover from or recovered later. Did you put your hand in the tank to check for electric current from a faulty heater?

Had all the fish been in the tank a while--nobody recently added?

Such a hard situation, and frustrating.

[Brandon p]

On 11/29/2021 at 9:13 PM, PineSong said:

First of all, what a sad find at the end of a vacation--I'm sorry this happened for you.

What kind of filtration/aeration was on that tank, and was it the same as the other tanks? Just wondering if there was a power outage or something while you were gone, that this tank did not recover from or recovered later. Did you put your hand in the tank to check for electric current from a faulty heater?

Had all the fish been in the tank a while--nobody recently added?

Such a hard situation, and frustrating.

@Ryan S.

[Ryan S.]

On 11/29/2021 at 8:13 PM, PineSong said:

First of all, what a sad find at the end of a vacation--I'm sorry this happened for you.

What kind of filtration/aeration was on that tank, and was it the same as the other tanks? Just wondering if there was a power outage or something while you were gone, that this tank did not recover from or recovered later. Did you put your hand in the tank to check for electric current from a faulty heater?

Had all the fish been in the tank a while--nobody recently added?

Such a hard situation, and frustrating.

Good questions - the tank is filtered by air and has a medium co-op sponge filter and a ziss bubble bio ball filter in addition to plant load so essentially had two airstones going at a pretty high level the whole time.

The tank is heated by reptile heat tape which is below the tanks on the rack so no electrical component within the tank.  

Tank did get some new additions from my local club fish auction about a month prior.  3 additional juvenile rainbows (2.5inch) from same breeder I got the first batch from and a male calico bristlenose pleco (3 inch), but I had kept a pretty close eye on them since I didn't quarantine and there weren't any visible signs of issues with these fish, but I suppose something could have happened fast to one of them. 

Good news is the 5 cories that survived seem to be doing well. 

On 11/28/2021 at 8:47 PM, Brandon p said:

Why is it when people leave does that first fish die that causes the rest to die

I'm wondering the same thing.  I really thought the plant load was so heavy that it would balance out if one fish died, but now the poster above who mentioned oxygen level going low due to a decaying fish makes me think that one of the larger fish dying could have done it. 

[PineSong]

On 11/30/2021 at 12:28 PM, Ryan S. said:

 

Tank did get some new additions from my local club fish auction about a month prior.  3 additional juvenile rainbows (2.5inch) from same breeder I got the first batch from and a male calico bristlenose pleco (3 inch), but I had kept a pretty close eye on them since I didn't quarantine and there weren't any visible signs of issues with these fish, but I suppose something could have happened fast to one of them. 

 

I do not know enough about fish diseases to know what (if anything) might have been going on with those fish that could have killed them and others without any visible symptoms before hand, but allowed the cories to survive.

Your tank sounds super safe with all that air, plants, and the heater being outside.