I am wondering about times to allow a sponge to ferment.

Is it important to let the sponge that has been feed get to its peak
and begin to fall before the next feeding or mixing? Or is it better to
catch it at the peak before it starts to recede? Will a sponge used to
soon or too late effect the bread? In what ways?

I am using Carl's starter. I have used 12 hours for 1st feeding and 8
hrs for the second feeding. Depending on the room temp. peak can very.
Should one pay more attention to the rise and slump rather than a set
time.

Thanks,
Jennifer