I have a tosai koi that is swimming around erratically very disoriented, heavy gasping. does nt appear to have any injuries after hands on inspection, gills are dark red, no obstruction in its mouth. rest of the herd are doing fine.
Here are the water parameters as of last night
ph - 8.2
nitrite - 0
amm - 0
KH - 150 - 180
nitrate - 80
my nitrate has been around 80ppm for most of the summer but I do water changes every other day. Pond is about 2000 gal, each w/c is 150gals or so. I have an aerated BD that is running all the time. I have pulled the automatic feeder.
I have performed two treatments of BSDT, one last night and one this morning, each after each w/c. I have been double dosing with seachem safe prior to any w/c plus running through a water filter (boogie plus). After the second treatment, I noticed that one of the largest koi flashing and I would say that is from the treatments as no fish was flashing last night after observing for 15mins.
I have an external water pump which I dont believe the issues are not electrical shock related.
Only thing that make sense is some sort of poisoning. I have a house plant call Purple Heart growing in my waterfall. After reading online, it says it is toxic if consumed. The koi are not able to get to the plant but I did notice two days ago a leave of it ended up in my cetus sieve. The plant has been removed that was making contact with the waterfall.
Thanks for any help.