Hi guys
I am sure there are many more experienced breeders out there than me that can help shed some light on these strange passed couple of days.... And maybe be critical and point out where I went wrong so next year I "can do better".
I have flocked spawned koi from my pond for the past 4 years, and raised approx 100 fish, all very varied results, but having commons and mirrors in my pond too, the results have been odd. So this year I tried to up my game slightly and tried out some controlled spawning
- Female 3 year old Sanke, Male 3 year old Sanke, Male 2 year old Kohaku
Extremely successful (I thought). Spawned in an outside 1700mm diameter cut down holding tank, in about 12 inches of water, so approx 700L, 2 large spawning ropes.
After spawning, removed the fish and connected the tank to my existing pond water system, trickle in/out about 30L/hr, to turn over the tank in a day.
Thousands of fertilised eggs, and approx 2000 hatched fry!!
Everything fine until last night, 3 weeks old, all look to be feeding well, underwater videos taken every day to observe them. Fed on egg yolk soup, and decap brine shrimp, plus just started some koi fry dry food. Water monitored via seneye sensor, ammonia 0.02, PH 7.7, nitrite and nitrate 0. Only thing to note is ammonia starting to rise slowly 0.05 today. But this is not high by any means, or maybe it is, and its something I need to understand better.
By this evening, 2000 fry now down to approx 300!
Did a squish of live fry under microscope and found nothing at all.
I am assuming all fry will now be lost, so completely gutted.
Did separate ammonia test to check on seneye sensor calibration, and it showed same result.
Any help or questions for discussion could assist in next years attempt
Many Thanks
Nic