Can cleaning create a die off?

[BAT]

I started cleaning the mulm from the tank this morning - and there is a lot!

I was going this bc my family was complaining the tank smelled. Turns out that I later found a dead Cory. Might have been dead a day. Eyes looked sunken and water logged. Now he was AT LEAST 5 years old.  

then as I was cleaning I noted two other fish (also from the older 5+ clan of black neon tetras) swimming upside down. They subsequently died. 

the water parameters were fine. Unchanged. This is a 3 year established tank. 
 

I was wondering if I dredge up a lot of mulm if it can kill fish?

[Miranda Marie]

Unlikely. Mulm is pretty harmless, and those symptoms seem pretty progressed for right afterwards. It's more likely they were already sick or stressed prior to that. I have drudged up tons of mulm before while cleaning with no averse side effects.

[Kurt Brutting]

I did a super clean once to a very established tank, I stirred everything up really good, and the worst thing that happened was a bacterial bloom. It took a few weeks to go away, but parameters all stayed in check. I would keep an eye on all your inhabitants for awhile make sure everyone else is ok. 

[Galabar]

How exactly did you clean things?  Did you just suck up the mulm into a bucket?  Did you vacuum the substrate?  Did you move lots of things around and kick up lots of mulm?

Here's a good video: 

 

[BAT]

I vacuumed the substrate just like Cory does in that video. That’s how I learned. He is so good. 

[Tanked]

Did you test the water before the cleaning?  Have you ever noticed your substrate pearling

On 11/25/2023 at 11:47 AM, BAT said:

I started cleaning the mulm from the tank this morning - and there is a lot!

I was going this bc my family was complaining the tank smelled. Turns out that I later found a dead Cory. Might have been dead a day

The dead Cory could have been causing an ammonia spike. Another possibility: If you had an over abundance of mulm, and it has been a while since you last cleaned the substrate, your cleaning could have released a poisonous gas pocket of (Hydrogen Sulfate?)  It is possible that the Cory would be the first to be effected.

Normally a deep cleaning does no harm.  My fish get an extra feeding immediately after maintenance, so they associate the two events, and stress is reduced.

[BAT]

What is substrate perling?

i wonder if some gas pockets were released bc a few other fish started swimming upside down and then I put in an air stone and kept adding fresh water and they seemed to right themselves. 
 

I do wonder if there was an ammonia blip. I didn’t see the dead Cory until I was cleaning so didn’t test for ammonia. And it is not on the AC main strip. 

[Tanked]

In this case pearling refers to that tiny gas bubble rising out of the substrate.  Instead of seeing the occasional bubble, it is possible for gasses to become trapped.  If the water smelled of Sulphur or rotten eggs, that would be a good indicator.

Pearlng in plants refers to the plants producing oxygen faster than the oxygen rich water can absorb it.  Bubbles on the leaves or a string of pearls rising to the surface is considered a good thing.

 

[BAT]

On 11/27/2023 at 11:15 AM, Tanked said:

In this case pearling refers to that tiny gas bubble rising out of the substrate.  Instead of seeing the occasional bubble, it is possible for gasses to become trapped.  If the water smelled of Sulphur or rotten eggs, that would be a good indicator.

Pearlng in plants refers to the plants producing oxygen faster than the oxygen rich water can absorb it.  Bubbles on the leaves or a string of pearls rising to the surface is considered a good thing.

 

Got it. Thanks!

there was a smell!

so can a pocket that is released kill fish instantly?

[Tanked]

On 11/27/2023 at 11:36 AM, BAT said:

Got it. Thanks!

there was a smell!

so can a pocket that is released kill fish instantly?

It can kill in minutes or hours.  It depends on the concentration. 

Remember that we are still speculating as to what happened in your aquarium.  Here is a quick WIKI explanation: https://www.theaquariumwiki.com/wiki/Hydrogen_sulphide

 

[Matt B]

I was curious about this same subject  and what others do with their substrate. ?  I do not gravel vac. , the way I keep my tanks, it always does more harm than good. Heavily planted in a mix of different sized  gravel.  I have done tiny probing in the gravel and it will release tiny bubbles....As far as someone complaining about the smell of one of my tanks.... I say: "How about you get away from my tank!?" Ha Ha. 

The plants do pearl at times. This is a Java fern pearling..