Hi. My GBA are spawning in the community tank too but I doubt there'll be many survivors.
Like you, I'm not new to breeding them but it's still cool to see fry in the tank.
My only advice is to do your research, which it seems you're doing anyway. Remember the saying 'The grass is always greener on the other side of the fence'
The shift to Oz has worked for some but many people find that it's not too dissimilar from here.
Can I assume you immigrated to New Zealand for a better life?
If you've failed to make that life happen here what makes you think you'll find it in Australia? Where will you go if that fails? You're already in Paradise mate so do what you can to make it work here.
I've had this issue with Neons before and I no longer keep them because of it. I now use Cardinals. The colouring is better, they get bigger, they school tighter and they live longer.
When I've seen them used the breeder removed the adults after spawning and let the eggs hatch amongst the marbles. They grew up in the same tank and were free swimming before the marbles were removed. This was in an otherwise bare bottom tank.
Hi
I'm looking forward to pics. I kept a Koura a couple of years ago and she was a fascinating creature.
Be sure to keep the temperature below 20C, they do not handle warm water very well at all.
Even low levels of ammonia and nitrite are toxic to fish. A stable tank should have 0.00 ammonia and nitrite. Water changes are the best thing you can do in this situation IMO.