Pond Trouble - Oct 6, 2017
The fish have been acting stressed for over a week, hanging out at the surface and around the waterfall, sluggish, but not gasping for air.
I tested the water and everything was OK, totally normal.
I changed some water for good measure.
Because lack of oxygen is the leading cause of the above symptoms, I added more aeration, then even more with a bigger aeration kit.
Got a chlorine test kit because I was concerned about Chloramine, but that also says everything is OK. Good, but puzzling.
The fish kept acting stressed, but some were eating. I had not seen the koi in several days. Fortunately, no dead bodies floating either.
I did a lot of reading and everybody says O2 is the problem. So I ordered and finally received an O2 test kit, which arrived yesterday morning and showed very healthy levels, so it wasn't the plants and sludge removers using all the O2. There were no signs if disease on the fish. I pulled out one fish and put him into
clean water and first he perked up, then he died later.
Something was poisoning the fish, that I was sure of by now.
Yesterday morning it was worse, and I finally realized that the only thing left was what if the filter had gone toxic from the heat wave, and because of my back, I had not taken the whole thing apart and cleaned it completely this year?
So, I took apart and cleaned the whole filter yesterday, which includes some heavy lifting and another partial water change.
To my delight, my back did OK; stiff and sore, but OK.
Then it was back to waiting.
This morning, finally, the fish seem OK, and all the big koi showed up for the feeding!!! Nobody hanging around the surface, and everybody normally acting, and all my "something is wrong" warnings quiet.
Filters are tricky beasts. There was no rotten egg smell, which is typical for hydrogen sulfide, and oxygenation should have helped with that. So, I don't know. I am glad things are better and hope this was a complete resolution.