Overflow flowing more with filter sock on? what gives?

[Blackdog2]

Tanks been up and running and the overflow has been just trickling over the safety, quiet as could be. Today I put a filter sock over the outlet in the sump and all of a sudden the overflow box is pretty much empty and making lots of noise as a result....nowhere near the safety.. so what gives? how can it flow more with the sock on? I would have expected a slightly restricted flow.... what am I missing?

 

[Clowning_Around]

Evaporation perhaps?

Flow doesnt really effect volume, it just effects movement/speed. I mean it's not like more is hiding In your pipes, granted there maybe a slight difference like how it runs over baffles and the friction coefficient grabing a bit more while water its attempts to push and allow more to fall over at once but that volume 'should' be negligible

Sent from my SM-G930P using Tapatalk

 

[thegrun]

It is very common for skimmers to produce a lot more foam when you switch or add filter socks. I need to dial back my skimmer every time I change out my socks for an hour or two. I haven't seen a good explanation as to why it happens, but many reefers experience the same problem.