Is that the long version of "it's breaking in"? :razz:

lol... I was going to say "It's just simmerin a bit let er alone" but remembered where I was.

I have Vertex IN-280, and I notice that any restriction in the air line (like inadvertantly putting your hand on the top cap hole) causes it to quickly overflow.

There's nothing blocking the air intake.

It didn't overflow with water, it overflowed with bubbles that filled my sump like foam. It literally looks like a bubble bath. :S

Well, maybe you have the water set too high in your skimmer. Open it up a bit. Mine usually produces more bubbles and foam after a water change, and I have to be sure my water level is not too high or it will overflow.

I think outside air pressure affects water levels in the skimmer, too. Was it a high pressure day?

Or whatever you were dosing might have affected it....

Some skimmer mysteries just remain so....

Well if you have little kids look for dish soap.:razz:
Just kidding

I don't have little kids.

Ok mine did the same thing once and i have never been able to figure out why but it has not done it again?.

I've always attributed it to something that changes the surface tension of water. Cyclopeeze and garlic extra can cause my skimmer to go bananas like that, even hours after feeding. I've even found that the mucus caused by some corals (namely a leather) can cause the skimmer to overflow.

I'll poke through my aquaculture engineering book in the skimmer section to figure out why they do this. I've been curious as well.

When my skimmer goes crazy, its because I put in a new filter sock. It also went crazy when I put a AQ filter sponge into the sump to seed it.