Yeah, I hope so too... Still have thousands. Population still looks unchanged compared to day 2 or 3 but I know numbers have dropped a lot but still looks like thousands to me. Most of population hit 1cm and some are developing black. I don't expect to see red colour until 1" and according to the net, it is time to start culling for kohakus. Being that father is kajuku, not entirely sure what the mix will be. If resources permit, I'll let them grow more to make sure. If only the weather is warmer now, the buyers will take all the biggies in my 1500G to their new homes. Probably won't happen in another month. So monopolize my main pond yet and I'm sure that'll cut down parasites. I might be stuck with 2 biggies, but that won't matter any more. Planning to build big mesh baskets.
I guess losing a hundred a day is not so bad for only a short time. Less culling but maybe those smaller ones are quality fry. Looks like mainly the little ones are getting hit with this problem. 90% of them are big. The 60G tank that is holding about 500 are doing great and have no floaters to my knowledge.
Now that they're bigger, it is with 100% certainty that some are scratching at the bottom of the tank. Before, I just thought they were darting around for fun.
Now, I'm feeding them mixture of crushed koi food, plankton and flakes. I'm going to discontinue that specialized fry food. Too fine.
I hope an expert chimes in on how to treat fry with costia. Don't want to make situation worse by medication. I'll stick with water changes and salt for now.