Random fish death :(

Bob2bob · Nov 28, 2019

Hey All,

I had a fairly bizarre occurrence happen for me on Tuesday.

I had three fish (two chromis and a flame angel) in my 75g mixed reef up and die seemingly at the same time. They had all been in the tank for some time, the chromis for three months and the flame angel for maybe 6 months. In the morning, they all ate the flake food i feed them every day and seemed happy and fine. At lunch time i found them all dead in the same area of the tank.

I'm perplexed as to what could have happened. All the corals in the tank seemed fairly happy though the day of some of the euphyillia and a large toadstool were a bit retracted. They've since been super happy. I also have 2 clownfish, 1 one spot faxface, 1chromi left, and 1 lawnmower blenny plus a cleaner shrimp.

I got some test kits today and ran some tests:

Nitrates (salifert): 0
Phosphates (Hanna ULR): .07
Calcium (salifert): 380
Magnesium (Salifert): 1380
Sal (refractometer): 1.025

I have alk but haven't done the test because my lights are not at peak yet. I do run a pretty active fuge that grows a lot and that explains the low phos and nitrate levels.

My only thoughts are maybe one of the corals (torches or toadstool) let out some chemicals that the fish ate and were poisoned by? Or maybe the foxface which hasn't shown much aggression to date (put in at the same time as the flame angel about 6 months ago) got freaked over something and stung the three fish?

Would love any ideas here as I'm completely unsure what happened and im scared of adding fish again.

Mical · Nov 28, 2019

Your params look ok. I'm guessing maybe stray voltage or possibly contaminants in surrounding air. (cleaners, etc)

Bob2bob · Nov 28, 2019

Mical said:
Your params look ok. I'm guessing maybe stray voltage or possibly contaminants in surrounding air. (cleaners, etc)

Hmmm thanks for replying so quickly! I will need to check the voltage,I definitely have a rats nest of wires and would not be shocked (pun intended) if that was the case. I haven't been shocked while having my hands in the tank just yet though.

I don't think it was a cleaner of any sort because I don't think we did anything that day cleaning wise. We usually do cleaning chores on thursdays.

Mical · Nov 28, 2019

I'm just guessing because that many fish in a short time tells me it was something pretty drastic. Mabe check your temp? If heater went bad and/or shorted out, but I would think other fish would've been affected also.

Bob2bob · Nov 28, 2019

Hmm another good possibility! really appreciate your thoughts on this @Mical Currently temp seems fine but maybe it went out for a bit and my heater is on the wonks. I'll definitely be keeping an eye on it

Qasimja · Nov 28, 2019

was anything new added the tank in the last few weeks? corals? inverts? etc

MnFish1 · Nov 28, 2019

Sometimes 2 Chromis in a tank will pester each other - which can lead to death - which leads to toxins - which leads to more death etc. Not all fish will be as affected. Additionally - sometimes the stress of being 'picked on' can allow other diseases that are latent in the tank to start causing problems.

That said - neither of these reasons seem that likely due to all dying so quickly - and at the same time. Unless you didnt happen to notice a potential problem when you fed them in the AM?

Do you happen to have an apex or aquarium controller of some kind - could there have been a power outage resulting in low oxygen and death for example. There are a lot of good suggestions that others have posted - hopefully you will get to the bottom of it

mcbdz · Nov 28, 2019

Same question as above and also did your fish have any type of QT before being added?

MnFish1 · Nov 28, 2019

2 other possibilities - Velvet has been shown to survive far longer than originally thought - which has led major aquaria to extend their QT times to 90 days. Another thing - do you have a deep sand bed - something that could have gotten stirred up releasing sulphur (in that localized area - since they were all found there?

Question - do you think they all died in the area - or did the flow in your tank just make all 3 dead fish happen to land in the same spot?