Brown gunk = Radiator Flush or ?

Hey this 97 se has brown gunk on sides of resivoir, I don't see anything floating around, Do I just need to flush it? is that normal to have sticky brown sh#t there, is it from dex coolant? I popped off radiator cap and see some sh#t floating around,and underside of radiator cap has brown gunk on it also. Is that bad or normal?
Thanks

Ok sorry I should of did a search first, seen it is normal w/dexcoolant, sorry for the extra thread on subject!

No problem and yes that gunk is dex when mixed with air.

Flush it the system and fill with green and you'll be good to go.

x2

Right on, thanks guys, I was wondering if it was ok you change to reg antifreese.

as long as you flush the system completely

Yes sir, will flush system completely. Thanks bud!