Hey,
This is absolutely amazing! Sometimes they really seem to need a period when you dont bother too much about them to spawn. I also think that it is most important to provide constant circumstances and water values. If as you said you only fed not so much, perhaps the pollution has decreased and they have still gotten enough to eat. It is true that sometimes, less is more!
My congratulations to your success and best wishes for the future. Lnce they have reached the mentioned size, they are very likely to survive and I think there will be others to be found in the next days and weeks…
Greetings Rafael