Fish dead within 48 hours

[MarineKyle]

Hello I was hoping someone could help me determine what might have happened to my fish. New to Saltwater aquarium but have had freshwater for 20 years. I have a 75 gallon FOWLR tank and within 48 hours almost all of my fish perished. The tank is around 6 months old. My parameters were good salinity 1.025, PH 8.0, Nitrite 0, Ammonia 0, Nitrates: 20. They were doing fine swimming around with no problems. Then my Flame fin tang started losing color and looked really pale and Butterfly fish looked milky white, like a film on scales. Wasnt sure is it was ich then they both perieshed.. Changed 20% of my water after and dosed with Ich Attack. Then today all of fish started perishing 2 wrasse, Coral Beauty, Springer Damsel, and now a percula clown, bubble tip anenome. Some showed signs of white specs or growths near mouth and some had fin damage. I only have one clownfish, lawnmower blenny and firefish (maybe) all not doing great. I lost my entire tank. I also have hermits, a sally foot crab, Saron shrimp, cleaner shrimp and Porcelain crab... who seem to be thriving. So i feel its some sort of fish disease... But seems to be extremely rapid development. Any advice would help... And what should i do before restocking my tank and how long should i wait. Also I did have a Cyano outbreak before, and dosed with Vibrant. a week ago. Thanks for the advice.

 

[Salted]

Generally, fish loss with all invertebrates thriving means a fish disease. Losing all fish in 24 hours often means Amyloodinium/velvet, but the fish would have shown rapid breathing prior to death. The typical response to that is remove all fish and let the tank run fallow with just the invertebrates for a period of time. The time frame ranges from 45 to 75 days, depending on the disease involved and the water temperature. Then, new fish should be fully quarantined, else you may end up with the same issue later on.

In your case, the tank running good for two years and then having a problem is unusual. Did you add any new fish or invertebrates in the past 45 days?

Jay

Yes, two wrasses from Salgado were added on 4/15, neither ever came out. They supposedly quarantine with copper. Both appeared healthy and were eating when purchased. Added a purple tang from them back in early Nov and it was thriving. Might be worth noting, these were picked up for my by a fellow reefer, who had also picked up a wrasse for himself. His never came out either after adding, and he assumed it to be dead just before my loss. His tank remains fine. On 4/29 all fish (with the excepting of the wrasses, which as stated had never come out) were heathy and active at the evening feeding. No signs of stress or disease. The fish losses happened on 4/30 & 5/1. Late morning on 4/30 I noticed my Gem in distress, it died a few hours later. Late afternoon the remaining fish seemed ok and ate, but now with the exception of my starry blenny not showing up. Late evening my other tangs were still out and appeared to be breathing rapidly, but it was too late for me to do anything. Plan was for a large water water change first thing in the morning. 5/1 am all fish except a blue damsel were dead. Damsel appeared in distress but alive. Did a small water change. Damsel quickly revived and by that evening/next day was acting as if nothing had happened. My tank is heavily stocked and I feed heavy (a lager tank was planned, seller backed out day of pick up back in Jan). My uneducated guess is a cascading ammonia spike starting with the death of the 2 wrasses and the other fish dying in order of susceptibility, expotentially compounding the problem. Thank you for taking interest, I had planned on contacting you and Humblefish about this event.

 

[Jay Hemdal]

Yes, two wrasses from Salgado were added on 4/15, neither ever came out. They supposedly quarantine with copper. Both appeared healthy and were eating when purchased. Added a purple tang from them back in early Nov and it was thriving. Might be worth noting, these were picked up for my by a fellow reefer, who had also picked up a wrasse for himself. His never came out either after adding, and he assumed it to be dead just before my loss. His tank remains fine. On 4/29 all fish (with the excepting of the wrasses, which as stated had never come out) were heathy and active at the evening feeding. No signs of stress or disease. The fish losses happened on 4/30 & 5/1. Late morning on 4/30 I noticed my Gem in distress, it died a few hours later. Late afternoon the remaining fish seemed ok and ate, but now with the exception of my starry blenny not showing up. Late evening my other tangs were still out and appeared to be breathing rapidly, but it was too late for me to do anything. Plan was for a large water water change first thing in the morning. 5/1 am all fish except a blue damsel were dead. Damsel appeared in distress but alive. Did a small water change. Damsel quickly revived and by that evening/next day was acting as if nothing had happened. My tank is heavily stocked and I feed heavy (a lager tank was planned, seller backed out day of pick up back in Jan). My uneducated guess is a cascading ammonia spike starting with the death of the 2 wrasses and the other fish dying in order of susceptibility, expotentially compounding the problem. Thank you for taking interest, I had planned on contacting you and Humblefish about this event.

I've never seen an ammonia spike in an established tank that wasn't caused by something killing off the bacteria first, and that is tough to do.

You didn't mention invertebrates - but they were all fine throughout this?

The wild card here is the damselfish. The fact that it recovered is odd. There is a chance that this was a low dissolved oxygen or high carbon dioxide event, and the water change fixed the problem enough for the damsel to survive. The dissolved gas issue won't kill invertebrates as fast as it will fish.

Jay

 

[Salted]

I've never seen an ammonia spike in an established tank that wasn't caused by something killing off the bacteria first, and that is tough to do.

You didn't mention invertebrates - but they were all fine throughout this?

The wild card here is the damselfish. The fact that it recovered is odd. There is a chance that this was a low dissolved oxygen or high carbon dioxide event, and the water change fixed the problem enough for the damsel to survive. The dissolved gas issue won't kill invertebrates as fast as it will fish.

Jay

I mentioned the inverts in post #39, they were/are all fine. Cleaner shrimp, cbs, snails, hermits, tuxedo urchin, sand sifting star. I'd expect they'd be affected by ammonia too. I have some coral that seems annoyed. Gsp, cloves, a pipe organ and some zoas aren't opening well. Yet ,all palys, bounce and ricordia shrooms, euphilia and a few rock flower nems continure to look great. I hate to say, but the damsel, looking so unaffected, and everything else mentioned were doing so well that at the end of the week,5/6, I added a few banngai cardinals and a chromis mid afternoon. They looked fine all evening, checking on them closely and repeatedly. They ate my frozen. Next morning, 5/7 they were all dead with the damsel continuing to be fine. I feel terrible. While I wait for your thoughts I will be doing a 30g water change on the roughly 80g system. That's all the water storage I have or I'd go bigger.

 

[Jay Hemdal]

I mentioned the inverts in post #39, they were/are all fine. Cleaner shrimp, cbs, snails, hermits, tuxedo urchin, sand sifting star. I'd expect they'd be affected by ammonia too. I have some coral that seems annoyed. Gsp, cloves, a pipe organ and some zoas aren't opening well. Yet ,all palys, bounce and ricordia shrooms, euphilia and a few rock flower nems continure to look great. I hate to say, but the damsel, looking so unaffected, and everything else mentioned were doing so well that at the end of the week,5/6, I added a few banngai cardinals and a chromis mid afternoon. They looked fine all evening, checking on them closely and repeatedly. They ate my frozen. Next morning, 5/7 they were all dead with the damsel continuing to be fine. I feel terrible. While I wait for your thoughts I will be doing a 30g water change on the roughly 80g system. That's all the water storage I have or I'd go bigger.

Sorry - transient events are tough to figure out after-the-fact, all we can really do is speculate. I do think you can rule out ammonia, unless you added some antibiotic or oxidant to your tank.

The bangaiis and chromis dying overnight is also odd. Velvet kills quickly, but not that fast....at least from first symptoms to death.

Jay

 

[Salted]

Sorry - transient events are tough to figure out after-the-fact, all we can really do is speculate. I do think you can rule out ammonia, unless you added some antibiotic or oxidant to your tank.

The bangaiis and chromis dying overnight is also odd. Velvet kills quickly, but not that fast....at least from first symptoms to death.

Jay

So where do I go from here?

 

[Jay Hemdal]

So where do I go from here?

That's the problem - I don't see how anyone can have a solid course of action for you, not knowing what the root cause was.

If it was velvet/Amyloodinium, you would need to move the damselfish out, treat it with copper, and leave the tank fallow for around 75 days.

If it was a transient gas issue, then adding aeration, such that it breaks the surface tension of the water will help.

If it was ammonia, you would need to figure out why, and then test to see that it has been alleviated.

Jay

 

[Salted]

That's the problem - I don't see how anyone can have a solid course of action for you, not knowing what the root cause was.

If it was velvet/Amyloodinium, you would need to move the damselfish out, treat it with copper, and leave the tank fallow for around 75 days.

If it was a transient gas issue, then adding aeration, such that it breaks the surface tension of the water will help.

If it was ammonia, you would need to figure out why, and then test to see that it has been alleviated.

Jay

Yeah, I get that. There were no external signs of velvet, and you stated velvet couldn't have killed the cardinals that quickly. As far as gas I have a correctly sized skimmer, a red sea reef wave 25 at the surface and my return agitates the surface too. Ammonia should have affected the inverts too but they're all fine. I'm lost. My plan is going to 3-4 30g water changes over the next couple of weeks and then maybe try adding one fish, maybe a molly.