Total fish wipe out

zomb

New member
This tank was previously an established 120g tank for years, I moved the tank and have had it for a year. All fish that came with it when established have lived and added some new fish that also lived. I used RODI water and bought the unit new when I got the fish. The only thing I did today was add water to replace evaporated water and then used a magnet cleaner to clean algae off the tank. Tests should no ammonia spike or nitrite spike. Nitrates sit around 80ppm, but they always have since I've had the tank. Salt water is 1.026, temp is 77.2 degrees, all the same as its always been. I had a blonde naso, a yellow tang ( 15 years old ), clownfish, damsel. Corals appear to be fine, though they closed up like at night. Inverts are all fine. It happened within about 20 minutes of seeing the blonde naso on his side looking like he was gasping for air, each one steadily started doing the same thing. I tried adding prime water conditioner that's supposed to detoxify ammonia, nitrites, and nitrates but I think it was too late. I didn't know what was going on but I knew a water change couldn't hurt so I hurried and tried to just to get enough in a bucket to move the fish for the time being and they were dead before I was able to do that. The only thing I can think of is a spike of some sort that did this, especially all within 20 minutes, possibly my test kits are bad, though they expire 2022. I also had test strips that gave same readings so I don't know what to think. It really hits hard to see that happen and to not be able to stop it or have a clue what caused it. I guess I'll just keep testing and try to keep the corals alive.
 
If you only had those 4 fish in a tank that size, and unless you had no surface agitation whatsoever, I doubt it was an oxygen deprivation event, which is generally the most obvious cause of rapid fish-only deaths.

The only other thing I can think of would be a poisoning event of some sort. Any insect (or other) spraying going on in/around your home? Where were your hands before they were in your tank? Anyone else in the home who might have "added" something to the tank (especially children, who might try to help the fish "feel better" by adding medication, or something else)?

Kevin
 
Nitrates that high should be fine. I am leaning toward disease related issues. Maybe velvet got in. Were the fish just breathing hard or was there flashing?

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Gas bubble in your sand maybe? It sure sounds like some sort of oxygen deprivation.

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Fish were breathing very hard before dying, it looked like they were oxygen starved, but like Anemone mentioned I didn't have that many fish in there and why would that all of a sudden happen? I mean they were all as happy as can be enjoying the tank, I fed them this morning and everyone ate and were swimming around like normal and it was just almost instantly after I cleaned the algae off the sides of the tank that first the blonde naso laid down breathing hard, followed by the damsel, then slowly the rest of them until they died. One last interesting thing to note, my diamond goby is still alive. I tried to get him out of the tank, but I can't find him. He seemed to swim away from me with ease.

I don't believe I had my hands ever in the water prior to this either. Its just weird, even if I did have something on my hands that ended up in the water or an ammonia spike, wouldn't that of killed a coral or my clam? I could see oxygen deprivation not affecting the corals or clam, but why/how does that happen? Also both my long spine urchin and pin cushion urchin are still alive, I'm actually fairly ignorant to what urchins need to survive.

As it stands now, do I still need to put food in the tank for my inverts and urchins? Corals are obviously fine with their light, but I assume the other guys need to live off something.

Thank you all for your replies it really sucks and I just wish I knew what the cause was and how to make sure the tank is safe and to prevent this from happening. If I ever do get fish again I think I need a hospital tank already setup and waiting.
 
A vet with more experience with salt water fish said there could have been CO2 build up in the algae that was released rapidly, apparently CO2 affects corals at a slower rate and could cause them to close up, while killing all the fish.
 
I am so sorry for your loss.

I agree that the symptoms sound like O2 deprivation, but that does not make sense in your situation. Another thought, which I discarded is that there was some kind of electrical issue that sent a current through the tank and shocked your fish. I think this is unlikely and probably would not have had the results you are seeing. I had an electrical issue years ago when a non-submersible heater (yes, they used to make those!) fell into a jail tank for an extremely aggressive damsel. It sparked and sizzled, and I pulled the plug from the wall. The fish survived and was extremely agitated and brightly colored - gave a whole new meaning to electric blue damsel! The exact opposite of what you witnessed with the fish one by one laboring to breathe. I know this does not help identify a cause, but might help to rule out one possibility.
 
I am so sorry for your loss.

I agree that the symptoms sound like O2 deprivation, but that does not make sense in your situation. Another thought, which I discarded is that there was some kind of electrical issue that sent a current through the tank and shocked your fish. I think this is unlikely and probably would not have had the results you are seeing. I had an electrical issue years ago when a non-submersible heater (yes, they used to make those!) fell into a jail tank for an extremely aggressive damsel. It sparked and sizzled, and I pulled the plug from the wall. The fish survived and was extremely agitated and brightly colored - gave a whole new meaning to electric blue damsel! The exact opposite of what you witnessed with the fish one by one laboring to breathe. I know this does not help identify a cause, but might help to rule out one possibility.

Yeah that's the worse part is not know 100% why to prevent it. It will be a long time before new fish are put back in and even then it will probably only be a pair of clownfish or chromies for a long while. I've had similar issues with electric problems that had me take proper precautions. I had a powerhead release current into the water that zapped me pretty hard, and I also spilled water on an outlet and had it fry before. Since then I put a GFI in and had a GFI probe in the tank so if there ever is electrical issue it should kill the power. Thank you for your input though, it's a tough thing to lose one fish, let alone the entire tank.
 
How much fresh water did you add and to sump or DT?

Roughly 3 gallons, I have the RODI setup, but I have the RO setup to go through DI and/or to use for drinking water so I have a 3 gallon tank of RO water that is held so when it comes time to add water I usually get 3 gallons pretty quickly and that's usually enough for a day or two of evaporation.

The RODI system ( spectrapure ) is about a year or so old, so I don't think anything got into the tank or issues with the system. I have inline TDS meter on both what the RO side is and what the DI side is and was reading 0 and RO reading 3. I do also always add a drop of prime in the water cause I never quite got used to being able to put water directly into the tank. The fish previously didn't get the luxury of RODI, the previous owner used Prime water conditioner on tap water. I did also double check the DI part with a separate TDS meter and got the same reading just out of caution afterwards. I've also added water since this incident and the corals didn't close up like they did when this happened.
 
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