Sometimes I think I am wasting BC when my planets develop.
For example, when you do not have full population, let's say there are 20 millions missing until full, but you already built lots of factories. If you have the resources allocated at industry, it seems that resources are lost. The planetary reserve does not increase.
I got used to put the resources into ecology, building up the population first, and only later return to complete the factories.
Can someone confirm or dismiss that?

The industry bar will say "MAX" when that turn will build as many or more factories as your CURRENT population can handle. Let's say at the start when each population can handle 2 factories, you have 80/100 on your homeworld and 165 factories. The industry bar will say "MAX" because your population of 80 can only handle 160 factories.

However your BC do not disappear, it just means you're not getting the extra production out of the factories you don't have population to work. The game will never let you build more factories than your MAX population can currently handle; it will automatically stop and readjust the bar to research (the above example will stop at 200 factories). Any spillover will go to your reserve.

The only "waste" comes out of not getting the production out of those extra factories until your population fills out. The math on that gets trickier since I'm not sure if putting production into growing population is worth it (production wise).

Thanks for the reply. :)
You say: "any spillover will go to the planetary reserve."
That's exactly what I am not observing.
As long as the population is not filled, the production seems to be wasted above max.
This can easily happen when you play the Silicoids.

As for the last step, when population is filled and it is the turn with the message "max factories reached", only then it goes to the planetary reserve...