Latest fish death

[ccokeman]

PH 8.3
Ammonia 0-.25
Nitrate 5 ppm
Nitrite 0
KH 8 drops
GH 5 drops
bottom drain and Skimmer to Cetus Sieve>>>Pump>>>UV>>>Sand and Gravel Filter>>2 K1 Bio Barrels >>>return to pond
100LPH air pump for the BIO and 60LPH for the air diffuser in the pond
12x10 x44 inched deep 3-3200 gallons


Forgot to get a closeup of the gills. Is this possibly KHV or Parasites to a bad bacterial infection? Lost one more after the treatment.
Before this one passed used BSDT 3 doses with Prazi added with the last dose.

Wondering if Im down to euthanizing the last 2 and bleaching the pond to kill what ever is in there.

[Matt24]

Sorry to hear about that. Possibly a severe bacterial infection.
Did the other that died have symptoms like this?
Do the other two show symptoms?
Have you had salt in the pond, and if so, what level of concentration?

[fly4koi]

Mostly likely parasite then secondary infection, you need to treat them with antibiotics immediately, Baytril injection if you can, otherwise Tricide Neo topical treatment or Oxolinic Acid at 0.5ppm in QT tank for 7-10 days. If they still eats you can use Oxolinic Acid or Tetracycline in feed. If it's KHV then you probably will lose them eventually, did you add any new fish?

[kdh]

Mostly likely parasite then secondary infection, you need to treat them with antibiotics immediately, Baytril injection if you can, otherwise Tricide Neo topical treatment or Oxolinic Acid at 0.5ppm in QT tank for 7-10 days. If they still eats you can use Oxolinic Acid or Tetracycline in feed. If it's KHV then you probably will lose them eventually, did you add any new fish?

Or bacteria fallowed by parasites. Or just bacteria. etc etc

[Noahsnana]

Are you doing regular water changes?

[SimonW]

1) How about the other koi in the same water?

2) Signs before death, like flashing, redness, not eating, etc?

Without more information it is difficult to know why.