Help! Fish mysteriously dying over the course of 4 months

J Cap

New Member
I've had a 180 gal predator FOWLR tank since 2011 with the same fish: Niger Trigger(~4.5 inches), Picasso Trigger(3 inches), Huma Trigger(1.5 inches), Clown Grouper(4 inches), and Snowflake Eel(18 inches). I keep the temp and pH at 8.2 and 76 degrees. They are fed tuna, shrimp, chopped clam, and squid on a rotating schedule. Ammonia/nitrite/nitrates were consistently at 0 except for a few extreme instances. It may have been overstocked (oops) but I had it for three years without issue, the triggers never fought because I kept the tank clean and well fed with their own hidey holes for each trigger (the gentle Niger trigger was the biggest and most dominant and no one was ever injured).

The snowflake eel died in a power outtage- induced filter crash around Nov 2014 and the other fish recovered quickly, and since then there had been no other incidents. In May of 2016 (just a few months ago) the Niger trigger suddenly started acting blind and confused and unable to find food even when I put it in her mouth with long tweezers. She paced the tank and after about 4 or 5 days she died without any visible signs of disease or distress other than acting strange. About a week later, the Picasso trigger began to act the same way and my LFS recommended I do freshwater-formalin dips for 60 minute 3 times in one week. This seemed to improve his state for a while and I looked for antibiotic treatment for the tank. After seeking advice from two local fish stores and one vet the only advice that came up was that it may be some sort of bacterial infection. I treated the entire tank with Kanaplex for two weeks as directed. This did not result in a filter crash, but the ammonia rose between the 0-.25 mark for a few days before two water changes that stabilized the water again.

The Picasso trigger returned to better health but the Huma and Grouper fell into the same confused state. All three fish began hiding most hours of the day and only coming out if I turned the lights out. I began feeding them at night and their appetite kept up, unlike the Niger Trigger that died about two months earlier. This went on for a few weeks.

For the past two weeks, the Huma and Grouper hid for all 24 hours a day but would still eat if I fed them with the tweezers. The Picasso Trigger would still swim around a few hours in the day and then 3-4 hours of the night once his light was off and has a very good appetite besides acting blind and needing to be fed by tweezer.

Today, I found the Huma Trigger dead in his usual cave while feeding. There were no visible diseases or injuries on him either.
I'm desperate to fix the tank and save my last trigger and grouper who I've had for 5 years, but I haven't had any luck with advice from stores or vets or other forums. It is especially distressing for me because they aren't showing physical signs of any infections or diseases but more "mental" injuries like blindness, confusion, lethargy.

If anyone has input it would be greatly appreciated. I want to know if there is any better option than trying to quarantine the two fish for a few weeks while I bleach their tank and start a new cycle to put them back in. They seem too weak for that.


I appreciate any advice or explaination!!!
Thank you so much!!
 

J Cap

New Member
Do you have a grounding probe in the tank? Have you checked for stray voltage?
I do not have a grounding probe dedicated to the tank but I check for stray voltage when adding new equipment and after power outages. I have not checked in a few months though. I will do that today.
Additionally, this is the first 100+ gallon tank I've ever owned (requiring larger filters/heaters etc) and when I asked advice of my local fish store about the danger of stray voltage they said that they don't bother to test for it. How dangerous is stray voltage? Do you recommend I check regularly for it? If it's a legitimate danger I am open to keeping on in the tank.
I did not think to test this so thank you for your input.
 

bang guy

Moderator
Stray voltage comes from equipment failures. It can happen over time, especially heaters and powerheads. It stresses the fish, not kills them. However; Stressed fish are more susceptible to disease and "mental" problems. It's probably not the cause of your fish deaths but if present it can be a factor.
 

florida joe

Well-Known Member
Just my .02 if you test for stray voltage and you indeed register some correct the issue. A ground probe is not the answer. A probe just gives the stray voltage a path out of your tank. BUT in doing so that path from the electrical idem introducing the voltage is what causing the stress on the fish. Their constant swimming through this path while in most cases will not kill them. It must surely annoy the hell out of them
 
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