We’ve been chipping away this week at the final set of tasks we need to complete for kicking off our first spawning of the year, planned for this weekend.
I’m going to use the new spawning tank outside the polytunnel for the big event. Temperatures currently are slightly lower than normal for May, and to provide the right conditions for spawning, we’re heating the water with drop in aquarium heaters.
One of the challenges I have is the brood fish are all in different tanks, and each tank is at a different temperature. And because the ambient temperature is lower than normal – and without the ability to heat my males tanks…. the males are residing at a temperature a little on the low side… currently 15C. The females tank is 22C. The spawning tank was 18C yesterday, and coming home from work tonight, I've found it's reached 21C.
So, the plan is to reduce the temp in the spawning tank overnight to within a few degrees C of the males tank.,
Then to introduce the males tomorrow morning with a few degrees C upwards difference being fine for them to take, and I’ll heat up the spawning tank during the morning up to the early 20’s. Then, move the female in tomorrow lunchtime. And hopefully, they’ll do the business over-night Saturday through to Sunday.
We have quite a busy weekend lined up, with various things going on. But with a bit of prioritisation, I do feel there’s a window this weekend to get the first spawning done, and then be in a position to rear the fry outdoors in the second half of May when I hope temperatures will be slightly higher. If we miss the window, then it’s not the end of the world. But it’s important to make the most of each week of warmth with the summers being so short in the UK. I’m basically placing a bet that there will be some warm weeks in about 2/3 weeks time.
After the successes at the shows last year, and the success of the june 16 spawning growth wise (they’re yet to be tested on the show scene) … I’m doing everything I can to make the most of this attempt to re-run the june 16 spawning – and achieve a much better harvest at first selection than we did when we ran this brood set last year. Each year, we have a series of things that go wrong. So far, this year there’s been the odd thing – we lost a female with dropsy over the winter. I’ve been meaning to write that one up… but haven’t got to it. Quite a shame, it was. Only picked her up at the end of last summer, but that’s koi for you. Sometimes, it just doesn’t work out.
The other issue we had is the lack of sufficient flow in the additional tubs added to the males tank system. So we have corrected that by improving the plumbing. But, nothing anywhere near the level of disasters we experienced early last summer. And each year there are major challenges, so part of me is just expecting some new thing to go wrong. But, on the other hand… I don’t see any reason why it won’t all go perfectly well first time!