i clean mine about once every week. (Collection cup) but i could do it more often thats for sure.

once a week. As Doug stated, a clean skimmer skims better than a dirty one.

How long does it take the skimmers to get skimming properly once again, after they've been cleaned? After I clean the cup in mine it seems to take a couple of days.

depends on the skimmer, i get skimate the same day , it just gets darker as it goes. i may not get anything at times too it depends on how i feed that week:)

if i leave it too long i get nothing after a while , so mine needs to be cleaned once a week:)

I have a similar setup when I go away on vacation. I use a couple of float switches to turn off the skimmer if it overflows.

I clean mine weekly.

Excellent idea! I'd have to change the vessel I'm using, but that's definately something worth adding to my "to do" list. I'd rather not have the skimmer overflow into anything: sump included. I really don't want skimmate going back into the system.

I skim pretty wet. I get about 1 litre of tea coloured skimmate per week.

I drain my cup when I get about an inch of nog and I wash the cup a couple times a week
I've only had the skimmer running since may and have thoroughly cleaned it once already as it is before my socks

Mine starts skimming right away. I cleaned it a couple hours ago, it's back skimming now. Just checked.

I clean the cup and neck every 2 or 3 days, the pump and body about 3-4 times per year.