snowflakes; Options

[Smarmosaur]

i'm making a background-i added "snow" (not animated) onto it, and i'm planning to make SOME of the snowflakes "glow" by increasing the size of an outer glow. my previous attempt ended up with 25 frames-not TOO bad.
now, my question is: i'm only animating 4-6 of the flakes, and i want them all to be in a different glowing order, so they're not all glowing the same exact glow at the same time-one starts, and a few seconds later another one starts, so there's a different glowing "pattern". i know that seems like idiot talk but i couldn't figure out how to explan it any way. is is possible to make them even (with the same "glow" size) at one point so i can loop the animation and it doesn't look "fake"? i increased the glow size on each frame until i liked it, then duplicated the frames so the glow decreases back to the original thing, and repeats...