Hi - feel like I'm here more than I would like, seemto be running into all sorts of problems! However your help is always fantastic and works a treat.
Just completed a water change as I do every week. But within 5 minutes of the water change several fish were behaving erratically. Five of our seven emperor tetras were swimming eraticly like they had swim bladder disease and two of our four corydoras were doing their surface dive seemingly once a minute (they normally seldom do this).
Two hours later more fish are now struggling.
The new water going in was within 1 degree of the tank temp and ph ok. Tested tank parameters using both strip and liquid testing kits. pH 7.4, ammonia nil, NO2 <0.3 (lowest read rhe test kit allows), Cl2 nil.
New water was treated with tetra aqua safe as usual and quantities measured as prescribed. Standard water change including gravel vac, wiping the filter box, wiping the glass and trimming plants.
Given the speed I suspect poisoning of some description but given testing parameters showed clear and water came from same source as always not sure what this could be.
Any offers of what this is or anything we can do to save rhe fish?
This doesn’t sound good at all! How large a water change did you do?! It seems like a contaminant. I’m thinking a detergent or aerosol. It may even have been a treatment added at the waterworks. Please rinse all your equipment with copious amounts of water and do a second water change. This sounds very stressful hopefully all works out!
Dare I ask what the situation has been since your post..?
I agree with Tknoxx's helpful reply: * something connected with the water change has happened / a contaminant of some sort has got in; other than their plausible suggestions, could there have been a residue from anti-viral wipes, soap, etc, on your hands? [The only other suggestion, based on my own experience, was that this once occurred to me when I used the cooled-down tannin water from having boiled a catappa leaf (with dechlorinator too, of course) - it was as though the concentration of catappa leaf extract was too high... fortunately a large water change resolved it.] * further water changes are the best option - if that hasn't resolved or has worsened the issues, then definitely contact the water supplier to find out if something has been added that could account for this.
The response was quite remarkable. We actually only lost one cory and one emperor tetra. I thought we were looking at losing 7 or 8 fish, given how lifeless and immobile they were. All I did was an immediate additional water change, and another one the following morning, and left the airstone on all night.
It has been suggested to me elsewhere it may have been hand sanitiser as apparently it lingers for hours even if you wash your hands! Other than that my only other thought is to ring the water authority and ask if they were aware of nay increase in trace elements.