Need help identifying cause of fish death

[Destinthecrab]

Hello. I'd appreciate any input on what may have caused multiple fish death in my tank today.

Tank 40 gal breeder
Livestock
2 clowns
1 striped blenny
1 lawnmower blenny
2 hermits

I have had this tank up and running since April. The striped blenny and one of the clowns were added about a month ago after a 30 day quarantine (treated with prazipro)
The lawnmower blenny I have had since January and the other clown was a fighter (had previously survived copper treatment for ich) and have been in the 40 gal since May.

They all seemed well and eating well as of last night. I did a 5 gal water change as usual after feeding. This morning they were well as far as I could tell. But when I came back from work, I could tell something was wrong right off the bat because there was some kind of bloom going on in my tank even though I have a UV sterilizer running. One clown was dead and the other three were dying. I have a 10 gal coral and invert only tank so I put the three there. The clown and striped blenny ended up dying. The lawnmower blenny seems to be recovering. My two hermits were fine. I left one in the 40 gal and he seems to be a acting normally.

I am scratching my head because I cannot pinpoint the cause of the problem.

Salinity 1.025
Temp 78.5
Ammonia 0
Nitrates <5

Is it possible there was oxygen depletion from an algae bloom? (I do have pretty good surface agitation though)

The only thing I did different with my water change this time was I scrubbed off some sludge that had built up on my HOB filter. Could that have triggered a bloom?

Again thank you in advance for any help. I'm wary of putting any fish back in there until I know what caused this.

 

[PokeFish]

Well im not an expert, but maybe some other parameter you didn't test is kill your fish. Like tin. Maybe have triton do a water test for all the parameters? Also you didn't mention your nitrites

 

[Destinthecrab]

Well im not an expert, but maybe some other parameter you didn't test is kill your fish. Like tin. Maybe have triton do a water test for all the parameters? Also you didn't mention your nitrites

Nitrites 0
I've never heard of measuring tin...or triton?
Sorry I'm still relatively new with fish keeping.

 

[Tankkeepers]

I agree with above you need a full test done as jts hard to say without more info

 

[PokeFish]

Nitrites 0
I've never heard of measuring tin...or triton?
Sorry I'm still relatively new with fish keeping.

SO basically from what i understand, there are more elements in you tank then just your standard ones like ammonia. There is calcium, magnesium, and all sorts of other metallic elements in your reef. Too much metals can come from rusting metal parts. (maybe a metal rod in your wave maker is rusting?) Just try to find out if there is any rusty metal in contact with your tank

You can send water samples to places like Triton where they test your water for EVERY single thing, and send you a copy of the results

 

[Destinthecrab]

SO basically from what i understand, there are more elements in you tank then just your standard ones like ammonia. There is calcium, magnesium, and all sorts of other metallic elements in your reef. Too much metals can come from rusting metal parts. (maybe a metal rod in your wave maker is rusting?) Just try to find out if there is any rusty metal in contact with your tank

You can send water samples to places like Triton where they test your water for EVERY single thing, and send you a copy of the results

I don't have rusty metal in my tank that I know of... I will look into triton testing. Thank you.

But if it was a heavy metal problem wouldn't that have been fatal to the crabs?

 

[PokeFish]

uhhh not sure. Crabs could be more resilient.. i don't know. I'm also pretty new

 

[Tankkeepers]

Only your fish dyed nothing else No invertabrate death etc as most of the time you will see invertabrate death before anything else usually snails first then crabs shrimp and lastly fish with only the fish dying and nothing else I have no clue as to what that could possibly be mabey they all fought to the death while you were away idk just a thought but probly not it

 

[Tankkeepers]

Its just really odd only the fish died and would have to be some sort of fish born illness or them fighting I woukd think not water quality I really hope someone comes along that knows what the heck happened as id like to know also

 

[PokeFish]

yeah... i did some research and you said that one of your clowns had ich before, and according to some people in different websites, after they had an algae bloom, there was an ich outbreak! So maybe the algae bloom triggered some dormant ich or something and thats what happen

 

[Tankkeepers]

Found this

Marine Ich can be incredibly tricky to treat because the cysts can remain dormant for such a long period of time.


So mabey dormant ich and bloom triggered rapid growth

 

[PokeFish]

yeah check your dead fish for ich and your survivor

 

[Steph72]

Hello. I'd appreciate any input on what may have caused multiple fish death in my tank today.

Tank 40 gal breeder
Livestock
2 clowns
1 striped blenny
1 lawnmower blenny
2 hermits

I have had this tank up and running since April. The striped blenny and one of the clowns were added about a month ago after a 30 day quarantine (treated with prazipro)
The lawnmower blenny I have had since January and the other clown was a fighter (had previously survived copper treatment for ich) and have been in the 40 gal since May.

They all seemed well and eating well as of last night. I did a 5 gal water change as usual after feeding. This morning they were well as far as I could tell. But when I came back from work, I could tell something was wrong right off the bat because there was some kind of bloom going on in my tank even though I have a UV sterilizer running. One clown was dead and the other three were dying. I have a 10 gal coral and invert only tank so I put the three there. The clown and striped blenny ended up dying. The lawnmower blenny seems to be recovering. My two hermits were fine. I left one in the 40 gal and he seems to be a acting normally.

I am scratching my head because I cannot pinpoint the cause of the problem.

Salinity 1.025
Temp 78.5
Ammonia 0
Nitrates <5

Is it possible there was oxygen depletion from an algae bloom? (I do have pretty good surface agitation though)

The only thing I did different with my water change this time was I scrubbed off some sludge that had built up on my HOB filter. Could that have triggered a bloom?

Again thank you in advance for any help. I'm wary of putting any fish back in there until I know what caused this.

I’m so sorry you’re going through this, it’s so hard losing these little guys. I’m not an expert but It sounds like something triggered oxygen depletion or shock because this happened so fast. Usually an illness like ich would have given you some warning first. The bloom that you have makes me think that something interfered with the beneficial bacteria in your tank, depleted the oxygen or something was in the water that was toxic and threw off the tank’s cycle. I agree that having your water tested is a good idea. Are there any environmental factors, like air fresheners, aerosol sprays, plug in diffusers, etc? Are you buying water from your lfs or mixing it at home? If you’re buying it, I’d call the store to see if anyone else had problems. I hope you find an answer to this, but these babies are so sensitive it may just be a mystery. My heart goes out to you.

 

[Steph72]

Found this

Marine Ich can be incredibly tricky to treat because the cysts can remain dormant for such a long period of time.


So mabey dormant ich and bloom triggered rapid growth

True, it stays dormant for a looooong time. I left my tank fallow for 80 days after I got an ich infestation. It’s very disheartening

 

[Tankkeepers]

The only reason I do not think it was an o2 depletion is becouse he said he only lost fish and nothing else which is odd as o2 depletion shoukd of killed everything not just the fish just my 2 cents tho as odd things happen all the time (I know had some odd things that didn't act like they should before)

 

[Tankkeepers]

Stupid question but could it of been the type of bacteria that bloomed that killed the fish as in contamination from your hands etc

 

[Hugh Mann]

Very few things kill that quickly, and selectively. Velvet and Flukes kill just fish, and fast, but doesn't explain the survivor. Ammonia would have killed everything, as would other chemical contamination.

Did you start with live rock, or otherwise have any possibility of a fireworm getting into your tank? A friend of mine just had a partial crash when his trigger was killed by a fireworm, which caused a chain reaction wiping out all the life on the bottom 3rd of his tank, but did not touch the upper portions. Reported cloudy water too.

 

[Destinthecrab]

Thank you all very much for all your input.

As of this morning my lawnmower blenny is still doing well. The hermit that I left in the 40 gal is also doing well.

To answer some of your questions...
- I do not have air fresheners going
- I buy RO water from LFS and mix it myself with reef crystals
- I do not believe their water was the problem because I did a water change on all my tanks that night and only the 40 gal crashed
- I started with all dry rock
- I did not see any symptoms of ich (my clown was treated with appropriate levels of cheated copper for 30 days so I don't see how it could have made it into my tank... Although the new comers may have been carrying it in a dormant stage)

It's of note that my lawnmower was also struggling mightily when I came home but perked up right after moving him to another tank which to me tells me it's not a disease but something wrong with the water...I may have to get a more thorough testing done. I just don't understand why my crab is still alive in there if there is something at toxic levels...

 

[Destinthecrab]

Also could leaving the skimmer off for one day have caused this? I've run a tank with no skimmer for a while but it didn't have much livestock at the time... When I did the water change I turned off the skimmer with the intention of cleaning it and left it off for the day.

 

[LeftyReefer]

Also could leaving the skimmer off for one day have caused this? I've run a tank with no skimmer for a while but it didn't have much livestock at the time... When I did the water change I turned off the skimmer with the intention of cleaning it and left it off for the day.

Yep. That skimmer is oxygenating the water besides removing organics.... I'm betting the tank was starved of oxygen and crashed.