Aquarium mystery

[D191]

Lost all the fish in a 24 gallon aquarium. Lightly stocked 1 bristlenose, 3 panda garra.  Well established, fairy heavily planted aquarium used to keep plants and extra white clouds brought in from outside in the fall. Water parameters unchanged, zero to very low nitrates, no ammonia. Temperature steady at about 74. Checked for stray current within aquarium and found none. Pleco hides all day so was unable to notice any change in behavior. Panda garra while looking good appeared to be lethargic and not interested in food for roughly the past week. No obvious signs of disease on the bodies of either species. Food they get is relatively fresh and the same stuff other tanks get without issue. Also cherry shrimp in the tank that appear to be unaffected. Any ideas would be appreciated. 

Edited August 5, 2023 by D191
Unfinished

[Guppysnail]

I’m sorry you lost your fish. Do you test your tap for chlorine if you are on municipal water.  Dechlorinators only do so many parts / million

A few months back my local water supply did a chlorine shock treatment. They usually do this at specific times of year so I know to look for it. This was an off time. I lost a few fish due to this. Lethargic, hiding, not eating then pass with no outward symptoms, nothing new to the tank or routine. 

[D191]

Chlorine was my first thought also but it came back zero. I then thought it had to be stray current from heater. Now I’m guessing it was disease or some kind of internal parasite that was laying low until now. These fish had been together almost a year with no problems that I could see. 

[Guppysnail]

Did your tank ph go up?  That would be caused by a hyper-chlorination event. Strips and tests don’t show chlorination on mine even at 4 ppm. I bought a swimming pool liquid reagent test. It shows on that. 

[D191]

Ph has stayed around 7. I think I’ve figured it out. I had a dishwater installed on Monday, I got home as they were finishing up. My understanding was that they had cut power for a short time. I’ve learned today the power was probably out for two hours. There was an aqua clear on that tank, which was of course running dry when switched back on. With the low fish load I guess there was a low bacteria count in the tank. I just have multi test strips so I didn’t check for ammonia. Earlier in the week there was some foaming around plants at the water line. I never worry about about ammonia, all my tanks are filled with plants. I’ve learned another lesson I guess but fish losing their lives because casual overconfidence is a tough pill to swallow. Thanks for helping 

Edited August 6, 2023 by D191

[AllFishNoBrakes]

On 8/5/2023 at 8:04 PM, D191 said:

I’ve learned today the power was probably out for two hours. There was an aqua clear on that tank, which was of course running dry when switched back on.

Did the filter continue to run dry? I don’t normally have power outages, but recently went through 2 power outages due to some repairs that required power to be out. 2 different power outages for ~2 hours each had 0 less-than-favorable outcomes on my tanks. That being said, I was home the first time and the second time my girlfriend was home and could confirm that air came back on, HOB’s primed and were running again, etc. 

[D191]

I have other HOBs on other tanks that always fire back up. Aqua clears don’t. Did a huge water change on the tank this evening my next step is getting a sponge filter. 

[Mikhaela]

On 8/5/2023 at 7:04 PM, D191 said:

Ph has stayed around 7. I think I’ve figured it out. I had a dishwater installed on Monday, I got home as they were finishing up. My understanding was that they had cut power for a short time. I’ve learned today the power was probably out for two hours. There was an aqua clear on that tank, which was of course running dry when switched back on. With the low fish load I guess there was a low bacteria count in the tank. I just have multi test strips so I didn’t check for ammonia. Earlier in the week there was some foaming around plants at the water line. I never worry about about ammonia, all my tanks are filled with plants. I’ve learned another lesson I guess but fish losing their lives because casual overconfidence is a tough pill to swallow. Thanks for helping 

I'm so sorry that this happened. I'm sure its tough finding out the reason of why they died, but like you said, you've learned something from it. I also am learning from this experience, so thank you for your vulnerability in sharing. I would say one large aspect of this hobby is being able to make mistakes and forgive yourself! I think you've got a great growth mindset and that's really what makes a difference in the lives of your fish 😊

[River]

On 8/5/2023 at 10:04 PM, D191 said:

Ph has stayed around 7. I think I’ve figured it out. I had a dishwater installed on Monday, I got home as they were finishing up. My understanding was that they had cut power for a short time. I’ve learned today the power was probably out for two hours. There was an aqua clear on that tank, which was of course running dry when switched back on. With the low fish load I guess there was a low bacteria count in the tank. I just have multi test strips so I didn’t check for ammonia. Earlier in the week there was some foaming around plants at the water line. I never worry about about ammonia, all my tanks are filled with plants. I’ve learned another lesson I guess but fish losing their lives because casual overconfidence is a tough pill to swallow. Thanks for helping 

Fishkeeping isn’t easy! The best advice I ever got is that we’re going to mess up and kill fish even if we’re doing our best. You sound attentive and knowledgeable. I’m sorry you lost your little friends.