Has anyone experienced scum when mixing SW?

[skatezen]

Does anyone us a powerhead with venturi on when mixing salt to aerate their water? I've noticed that when I make a new batch of SW and turn the PH on with the air, the micro-bubbles collect all kinds of scum like the froth you find in a protein skimmer. Is this crap in the salt mix supposed to be there? What is it? When I turn the air off it all dissolves back into the water. Should I let it dissolve in the water before adding it to the tank or should I try to remove as much as possible before adding the water?

Jeff

 

[Muscles]

Are you using RO/DI?

 

[this is me]

interesting....but why are you using an airstone mixing your water? Just a PH circulating it is fine.

 

[skatezen]

Yes I'm using RODI. It's not an air stone but the air intake one the Powerhead.