explanation on 40g crash overnight?

[redhanded77]

well to be exact, i lost 4 fish in a matter of 1-2 days. they were 2 lawnmower blennies, 1 hawkfish and 1 porkfish. tank was cycled and all readings were 0 across the board. i have about 30lbs of live rock and they were all eating well and appeared healthy. quick story of what went down.....
friday evening i noticed the porkfish swimming near the top of the aquarium and not really moving around like he normally does. when it was feeding time, he did not eat at all and ignored the food, which was really weird because he is usually a pig. the other fish ate with no problem. later that night my brother finds one of the blennies crawling on the carpet and throws him back in. none of the blennies have attempted to jump out in the past 2 months ive had them. in the morning that one blenny that jumped out was dead and being eating from the hermits, same goes for the porkfish, dead. i could not find the other blenny, but later on in the day, i found him behind the cabinet all dried up. at this point im flipping out thinking what the hell is going on. i attempt to feed the hawkfish, but he doesnt eat. he is just sitting on his favorite rock, breathing hard and not moving. later on in the day, i find him dead. so i lose 4 fish in a matter of days and i dont know why. i usually feed frozen brine and mysis and switch it up with flakes. i did notice the temps went up to around 83-84. the avarage temp is usually around 80. i added 10lbs of live rock a few days before that, but it was cured and i checked the water daily to see if any amnonia or nitrite was present. nothing came up on the tests. prior to the rish dying, they all looked healthy with good movement and good color.
any ideas? the water is fresh sea water from a fishery company. im stumped

 

[silverdak]

I am no expert by any means, But I do know others who are very knowledgeable will want and need to see test results to help you. I would work on getting those

 

[perfectdark]

How new to the tank were your fish, all the fish? Did you add them all at once? What was the time line between adding them? I know you said that you tested your levels but did you test after the first death was found in your tank? Did you do a water change at all since this all happened?

 

[redhanded77]

well the tank was about 4 months old. after the tank cycled, i added the hawkfish. the next month was the porkfish, and the month after was the two blennies.
after the first death, readings were all 0. even this morning, the readings are still 0.
i noticed that before the crash happened, i did a pretty big water change, maybe about 50%. i use the same sea water all the time with all my tanks. what im thinking now, is there was a big temprature difference between the tank and the new water. that would be the only thing i can think off.

 

[1journeyman]

That kind of temp swing is certainly bad...
That said, I don't believe that did it. I highly suspect an error in your testing kit for Ammonia.

 

[perfectdark]

Originally Posted by redhanded77
http:///forum/post/2773903
well the tank was about 4 months old. after the tank cycled, i added the hawkfish. the next month was the porkfish, and the month after was the two blennies.
after the first death, readings were all 0. even this morning, the readings are still 0.
i noticed that before the crash happened, i did a pretty big water change, maybe about 50%. i use the same sea water all the time with all my tanks. what im thinking now, is there was a big temprature difference between the tank and the new water. that would be the only thing i can think off.
Depending on how big is big, yes absolutely. A 5 degree swing isnt monumental, but if it occured in a very short time like the time it took to put the water back in you took out then that could shock the fish. How big was the temp change? I would also look into testing with a diff kit just to be sure yours are accurate

 

[redhanded77]

im gonna go and try my cousins water test kit and see what kind of results i get. i just tested another tank that im currently cycling right now, and low amount of amnonia showed up, and the nitrites were very high.
but still, im gonna retest with another brand and see what i get.

 

[aztec reef]

Theres a few possible causes.
1. osmotic shock from the large water change..( it wasn't aerated/aged)
2. ammonia toxification due to the fish deaths..
3. stress (due to sudden temp swing)
4. water chemistry is/was fouled.. (compare test results to lfs or a colleague)

 

[1journeyman]

Originally Posted by Aztec Reef
http:///forum/post/2773991
Theres a few possible causes.
1. osmotic shock from the large water change..( it wasn't aerated/aged)
2. ammonia toxification due to the fish deaths..
3. stress (due to sudden temp swing)
4. water chemistry is/was fouled.. (compare test results to lfs or a colleague)
1. Good point. How are you testing for salinity? Any inverts die?
2. My suspicion... over feeding in a small tank lead to an abundance of it.
3. I don't think that is likely. Not 4 fish over that length of time. Small fish survive in tidal pools with much greater temp swings.
4. To expand... could very well have been a toxin of some sort.

 

[invertcrazy]

Could it be possible that stray voltage can do this? Just a thought.

 

[aquaguy24]

it was problably due to stress caused by you doing all those things at once..it was like a snow ball effect...

 

[redhanded77]

stray voltage? everything i have is grounded, but it could be a possibility. im not sure about the ammonia theory. we used 3 different test, and everything but the nitrates are zero's. the hermits and crabs are still doing fine. i dont think i overfeed. i feed in the morning and at the evening, and i use an eye dropped to "squirt" in the mysis and brine. i feed small squirts at a time for a few minutes and thats it.
all 4 fish were in the tank wit each other for atleast a month....all the while having perfect readings and they appeared to be healthy. good color, lots of movement and eating. the tank was fully cycled before adding livestock, and each fish was added with adequate time in between.
hhhmmm.....i thought of another idea. i did add an anemone crab a few backs, that was recently attacked and eatenfrom a rock crab a day or two before the fishes went bad. maybe the anemone released some kind of poison in the water that killed the fish? thats the only odd thing that i think could happen, other than some kind of toxin that was introduced in the tank. or the water change stressed them to their death. salinity and ph were identical to the tank, only the temperature was the difference.

 

[meadbhb]

Hiya,
Silly thought...how is the ariation in the tank? Could it be oxygen starvation?
Kim

 

[aztec reef]

Originally Posted by redhanded77
http:///forum/post/2775008
maybe the anemone released some kind of poison in the water that killed the fish? thats the only odd thing that i think could happen, other than some kind of toxin that was introduced in the tank. or the water change stressed them to their death.

Thats moslikely your answer:
Your water was fouled via the toxin released by the anenome and the ammonia of the fish deaths..And possibly including the remaining streesed activities that your tank could not endure..