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

[N.Sreefer]

I took my sump offline to install a larger one and moved the heaters into my display I also added alot of extra surface agitation. Its taking longer than expected to get the new sump installed and I noticed my fish acting strange. Looked in my tank and my kole tang is dead my other fish are laying on the bottom other than the chromis that are gasping for air at the surface. I dont understand with enough agitation shouldnt o2 get into the water? I have so much flow in there right now the waves are touching my lid. My protein skimmer is in sump so thats offline but other than that just my ats is offline all other life support is running. Im stumped and Im not sure I have many options to save my fish. Its a mature system rock is near a decade old system over a year I cant imagine my parameters changed from my sump being offline 3 hours. I guess I need to vent more than anything.

 

[redfishbluefish]

Check for stray voltage...moving your heater to the DT. If it's leaking voltage, could be the problem.

My first guess would have also been oxygen.

 

[mdb_talon]

I would still guess oxygen personally. If you have or can quickly get an airpump/stones i would do that. Other than salt creep ot dont hurt anything and it will help of it is an o2 issue. ATS going offline is also reduction on o2. You mention waves hitting the lid? Is this a hard glass/acrylic lid?

 

[N.Sreefer]

Thanks for the responses I didn't think about voltage, I will move my ground plug into the display until the sump is running again. Its a red sea diy mesh lid just put it on pain in the **** to make. I put two large pond pumps (oiless) in my display when I seen the fish in distress and its got the water looking like its boiling with waves hitting the mesh. Some fish look to have perked up so it could possibly be O2 I cant believe I lost fish from this I had plenty of surface agitation already the sumps only been off for 3 hours. So far 2 losses I see but the lights are off for nighttime so I'm sure Ive missed some. This will be a long night. Only other thing I was thinking was ph but I checked its 7.8 on salifert.

 

[vetteguy53081]

Voltage or change in parameters such as salinity, nitrate, etc
I just changed sump 2 weekends ago and no issue

 

[mdb_talon]

Wishing you the best and you dont lose anymore. Agree ph won't be an issue to get low enough to kill fish....and if it would go crazy low that would also point to lack of aeration which again could lead to o2 deprivation.

 

[Dburr1014]

What was in the sump? Just gear? No live rock?

 

[Malcontent]

Surface agitation actually doesn't do very much. I compared a wavemaker vs an air stone and the wavemaker had to turn the entire surface of my tank into whitewater to match the air stone. And consumed 7X the power to do so.

On the freshwater forums, people are always hyping the importance of surface agitation and saying that all you need is to break the surface tension of the water and that's enough. Well, they're idiots.

 

[N.Sreefer]

What was in the sump? Just gear? No live rock?

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.

 

[N.Sreefer]

Surface agitation actually doesn't do very much. I compared a wavemaker vs an air stone and the wavemaker had to turn the entire surface of my tank into whitewater to match the air stone. And consumed 7X the power to do so.

On the freshwater forums, people are always hyping the importance of surface agitation and saying that all you need is to break the surface tension of the water and that's enough. Well, they're idiots.

Never thought of this but I tend to agree at this point I believe my skimmer is doing the heavy lifting oxygenating my tank and no level of surface agitation is enough. I will add a bubbler until the sump is online again thanks for the advice.

 

[ZoWhat]

You know the fish don't go through the skimmer, right?

 

[jmichaelh7]

Aeration

 

[N.Sreefer]

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.

 

[hllb]

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.

For the small fish, I wouldn't worry about getting them out if you have a decent clean up crew. They generally take care of them long before you'd find them anyway. Sorry for your losses.

 

[Tamberav]

Very odd. There are skimmerless and even sumpless tanks and those with glass lids or hoods.

 

[workhz]

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).

 

[Lost in the Sauce]

Very odd. There are skimmerless and even sumpless tanks and those with glass lids or hoods.

I'm still stumped here as well..

None of this makes sense to me. How did dissolved oxygen drop SO quickly as to kill 7 fish so quickly...

Honestly thinking there's something we are missing or that was omitted necessary information.

 

[N.Sreefer]

Very odd. There are skimmerless and even sumpless tanks and those with glass lids or hoods.

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.

 

[DaddyFish]

That would have to be some serious O2 depletion to kill damsels. They're hyperactive zombies to start with!

Any chance we're dealing with a toxin release here?

 

[DaddyFish]

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 (not dying just leaving sandbed) so it could have to do with DSB.

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