Why would feeding cause the sump/fuge to

act differently? I saw this thread http://www.3reef.com/forums/fish-food/rods-food-causing-air-bubbles-overflow-siphon-tube-69636.html
and it's similar to what happens in my tank, but just using frozen brine/spirulina (not Rod's) that's been defrosted first.

It's odd and I can not fathom what's going on. Feed the fish and then more water comes out of the fuge side vs how it regularly works. Micro bubbles are present also. The bubbles I can somewhat understand, but why the heck would it cause more water to come out of the PVC into the fuge? It gurgles more etc.

One other thing while I'm at it... Why when the return pump to the DT is off, the skimmer starts returning way more bubbles and water from the sump? (skimmer's in the sump...obviously)

AND, I dont understand why the water level keeps changing in the overflow box. I use a Hofer Gurgle Buster. Water level's good in there for awhile and then a week later or so I see it higher in the overflow box.

 

Take some pics of your setup for us people that need visuals. When the skimmer water level changes it is going to affect you skimming. As well as feeding, salinity change, etc, will all affect your skimmer. Does the water level in the skimmer chamber remain consistent?