I am stumped fish dying one after another after I took my sump offline

[N.Sreefer]

There we have it!
Deep Sand Bed, Hydrogen Sulfide release.

Heres the odd part DSB in display was not disturbed and I was using a glass lid until yesterday with less surface agitation than I had during this crash. So other than the skimmer being offline my display turn over and atmospheric exchange were increased. Although that is a good theory not saying that's not possible.

 

[Sleepingtiger]

That was why I ended up posting and got so confused I ran sumpless and I ran without a skimmer for years in my old system with no issues. I will say fish losses stopped and fish improved after I added a couple bubblers the pumps did nothing. I only lost small fish the blue eyed kole was 3.5 inch long the chromis and damsels were tiny, my hogfish parrotfish all my mollies, mandarin, foxface, sailfin tang, all 6 clownfish, lemon damsels, and sweetlips are fine. Coral are looking okay all open. No nitrate spike yet. My aquarium is deep and narrow its 24 inch tall but only 19.5 inch wide (72 long) perhaps I did not have enough surface area. The micro life in my sandbed started bailing last night (not dying just leaving sandbed) so it could have to do with DSB.

did you disturb the DSB?

 

[Tamberav]

That was why I ended up posting and got so confused I ran sumpless and I ran without a skimmer for years in my old system with no issues. I will say fish losses stopped and fish improved after I added a couple bubblers the pumps did nothing. I only lost small fish the blue eyed kole was 3.5 inch long the chromis and damsels were tiny, my hogfish parrotfish all my mollies, mandarin, foxface, sailfin tang, all 6 clownfish, lemon damsels, and sweetlips are fine. Coral are looking okay all open. No nitrate spike yet. My aquarium is deep and narrow its 24 inch tall but only 19.5 inch wide (72 long) perhaps I did not have enough surface area. The micro life in my sandbed started bailing last night (not dying just leaving sandbed) so it could have to do with DSB.

Some of your fish that I would suspect use more oxygen are alive and well. It should have been the big fish to die first not the small.

Oxygen issue makes no sense.

 

[N.Sreefer]

did you disturb the DSB?

Some of your fish that I would suspect use more oxygen are alive and well. It should have been the big fish to die first not the small.

Oxygen issue makes no sense.

The dsb was not disturbed only sand in the sump was with my mangrove in a pot so I never had to disturb the sand.

None of this is making sense to me. This aquarium was bare bones with the same livestock my equipment was upgraded I have more flow and more filtration now when I took the sump offline I basically went back to how the aquarium was with the same stocking before upgrading filtration in the sump. I don't have anything like a sea hare or cucumber that could release toxins, nothing new went in the tank, looked around and I am 100% sure the sandbed was not disturbed other than my conches which also lived through this.

 

[N.Sreefer]

Dead tang bugger was fat and happy

 

[N.Sreefer]

@Randy Holmes-Farley

I am not good with chemistry would hydrogen sulphide gas bubbling from anaerobic areas in a DSB lower O2 saturation/raise CO2 with no surface tension (tons of circulation and surface agitation)? Seems like the most likely explanation to me but with the amount of gas exchange at the tanks surface I would imagine I would've smelled rotten egg smell.

Also sorry everyone not spamming this to bump it up just really confused and want to prevent this from happening again during a short power interruption if one happens.

 

[Lost in the Sauce]

I don't run a skimmer or bubbler on 2/3 tanks.

Larger fish should have been affected First by a low oxygen environment. Not the tiny ones.

Could there have been something going on in the sump that was released and got into your display before taking it offline? Do you also run DSB in the sump?

 

[jdiefenbaugh]

Is there a good rule of thumb to how long a tank will stay adequately oxygenated to support the fish. I'd imagine a single 3" fish in a 100 gallon tank would fare differently than 20 3" fish in a 50 gallon. Probably depends on initial levels obviously. 3 hours seems like an awfully short period of time to lose fish when they get shipped around the country and from overseas which takes quite a bit longer (and in small bags).

I've taken countless DO readings, and you'd be surprised how fast the levels can crash. I dont know if that's what happened here, but it's my guess. An air stone would've at least ruled the possibility out. Shipped fish are sealed with straight O2, which is why they can last ~24 hrs as long as the bag stays sealed.

 

[Sleepingtiger]

I have taken my skimmer offline many times. And with herbie overflows, there isn't any surface agitation. My only guess is your heater failed during the move and caused a leak. Small fish are the first to show symptoms. I seen that happen before where the heater was left untouched for years sitting in saltwater. When moved, it caused the shield to fail

 

[Dburr1014]

50gal sump on a 150 about 25 gallons of water in it while its running. Had at the most 20 pounds of live rock with my equipment and brightwell biobricks but I have approx 200 pounds of rock in my tank. I decluttered my sump so its mainly just equipment. From the look of the tank ive lost 2 fish for sure but the others are holding on i got 2 pond pumps and 6 powerheads running in my tank looks like a raging river and the fish still look stressed.

Shortly after posted I managed to get the new sump online but I already lost a blue eyed kole tang and at least 4 chromis and 2 yellow tailed damsels. I managed to get the larger fish out but I'm afraid there may be corpses trapped in the rockwork. I'm debating a full tear down to get the fish out and prevent a cascading effect. I am still stumped how dissolved o2 could get to low enough levels to kill fish in such a short period of time even with high surface turn over. I feel terrible for the fish I guess the silver lining is the warning that my existing thoughts on how long my reef will last without power were really wrong. A warning I'm happy I got before a power outage so I can prepare. Thank you all for your advice/support and I apologize if my writing was/is incoherent a combo of no sleep and stress haha.

Sorry for your losses, you also lost some of your bacteria from the rocks and blocks. Could have had a small spike in ammonia and with O2 loss, cascading effect...
Again, sorry this happened.

 

[Dburr1014]

There we have it!
Deep Sand Bed, Hydrogen Sulfide release.

Why? He didn't disturb it.

 

[N.Sreefer]

I have taken my skimmer offline many times. And with herbie overflows, there isn't any surface agitation. My only guess is your heater failed during the move and caused a leak. Small fish are the first to show symptoms. I seen that happen before where the heater was left untouched for years sitting in saltwater. When moved, it caused the shield to fail

Bingo this heater melted onto the bottom of my ats never seen it

 

[Dburr1014]

Yikes

 

[ying yang]

HOUSE ^_^

 

[Lost in the Sauce]

Bingo this heater melted onto the bottom of my ats never seen it

So current working theory being you melted some plastic in contact with the water releasing something into the water that killed the fish?

 

[Sleepingtiger]

Bingo this heater melted onto the bottom of my ats never seen it

Man. I hate to be right in this situation. Loosing fish like this really sucks.

 

[N.Sreefer]

So current working theory being you melted some plastic in contact with the water releasing something into the water that killed the fish?

Its the only theory that makes sense although I will say no coral loss and no other fish loss does make me a little perplexed. I'm omw to a LFS that has ICP sample kits so I'll send one off and see what it says. Still no nitrate spike and no disturbance of anything deep just bioblocks and biomedia.

Man. I hate to be right in this situation. Loosing fish like this really sucks.

It really does its nice to talk to people who understand my family just sees them as fish but I get pretty attached.

 

[DeniseAndy]

I am sorry for your losses. It is so hard sometimes to know exactly why with so many variables. I have gone through a almost total fish loss twice. Once was never discovered exactly why.

I am glad most of the animals are still good and thriving. Good luck going forward.

 

[Lost in the Sauce]

This far out I doubt ICP testing will come back with anything abnormal. Those aren't testing for all trace chemicals. Just a specific set of them.