Skimmer break in period

[Doug]

So why do some skimmers require a break in and some dont? My CV 220 never required one. For sure my Tunze never and started skimming as soon as plugged in.

Dont recall some of the others. Just fired up my 160 cone skimmer today and it was foaming at the start but now no foam. All the posts on other boards refer to the break in period? If its the "oils" or whatever, why only in some brands. Why does cleaning before use not help then?