April selections completed

Back to work today after a fun Easter weekend.
We’ve had all the usual family get togethers that you might expect, plus made some big progress fish wise too.
I’ve selected through both growing on tanks, cleared space for the koi selected out to move into, and then also moved them taking pics along the way of some of the keepers.
Turned out that having family over gave me an opportunity to draft in additional labour, in the way of my wife's nephew who helped with photographing the keepers from the July 14 spawning and also gave Amanda and I a rare opportunity to both appear in the same picture at the same time.
The seine netting process is becoming easier with practice and we caught them all up in one go.  Here are some picturs from the July 14 spawning growing on tank

Usually I'm going through selections on my own - wet hands, camera, photos, selections - these things don't go together well!  It was so much easier with 3 of us on it, and these photos taken by Amanda's nephew with show the general process on the July 14 spawning selections.
A sneaky peak to get a general sense of the level we've achieved

Keepers are moved to the cage net on my left.  Fish I've selected out are moved in groups of 4 or 5 fish into an inspection bowl for Amanda to double check

Then she moves them into another tank where we chilled them to ambient and subsequently moved them out of the growing on system and into a holding tank connected to the males tank filtration system.
With the May 14 tank – the amount of fish waste that collected in the net after just a few hours was a big surprise, and it reinforced the decision to reduce numbers in the tank.  Even with a drum filter on the tank and cleaning out waste at least every 20 minutes, the amount of fish poo sitting around the tank before it migrates to the drum must have been quite significant and no doubt leaving the environment sub optimal for growing on.
The fish are not thanking me for the big temperature swings recently.  It wasn’t that long ago they were at 16C in the grow on tanks, which I took up to 24C for probably just a week before I changed my mind on waiting until May for selections and introduced the interim April selection.  So the temp had to come back down to get close enough to the ambient tanks where the fish I select out would move to.  Now, I’m starting the process of taking the temps back up again.  I’ve lost around 4 to 6 weeks of proper growing on conditions from the electrical problems and this unplanned interim selection.  The electrics are now upgraded and the interim selection is another lesson about stocking densities which I will be more savvy about at the same point next year.
That rate of temperature swing is in excess of the amount typically recommended, and it shows the fish are resilient to temperature changes particularly if they’re in good health to start with.  The fish that moved tanks and have remained at ambient temperatures are actually much happier than the fish that stayed in the growing on tanks and are being warmed up again.  The temperature changes are a stress factor for them, and I’ll keep a close eye on them over the next week or two.
In parallel, I am continuing the pre spawning series of treatments on all my tanks to give me the best chance of a parasite free May when I hope to perform the first of this years spawnings.  So the fish have that to contend with too, but the other part of that is it will nip things in the bud if they’re knocking around.
Females tank is up at 20C now, and I’m using the newly plumbed in air source heat pump to hold it there.  I’ve moved off the ‘health’ food and am feeding them ‘top koi’ from Coppens which is a high protein food with lots of added extras to help with their general health – in the hope it helps them prepare a good batch of eggs for me!
I’ve become inclined to use ‘top koi’ for stretches like this, or for example, the winter growing on stints when temps were at their warmest – 22-24C.  It’s not cheap, but when you have a bit of success in the tank, you start to think the food has been a factor and – once that’s hit your brain, you’re done for and its difficult to stop with that food. Don’t think it’s great for the white’s, which has to be the compromise.  Plus, its probably not good if you like your water crystal clear.  And, the success in the growing on period is evident in some fish but lots haven’t grown so well – so the food isn’t a panacea.
Ok, final pictures now.  In no particular order - here are most of the keepers from the July 14 growing on tank.  Should be a useful record for more case studies.  Quite a wide range of sizes, patterns, body types, reds,  here - and I wanted to give as many as I could that extra month or two growing on so I can gleam as much knowledge on their development as possible before I make the final selections in May.