I'm pretty sure it's particles. My skimmer output is a descent distance and alot lower from my return pump

I find it strange you have an oil slick. I think you may not be skimming the DOC's off the top layer. Perhaps you need a longer linear overflow or probably faster flow through the sump.

In anycase what you are experiencing is not normal and I think it may be a design flaw.

If you point one of your powerheads towards the surface you should be able to create enough turbulence that the oil slick will fix itself, just keep the powerhead permanently in that position.

I also think you have a case of the microbubbles as Zoa Elite suggested. :D Microbubbles can be difficult to distinguish from particulate matter if you don't know what you're looking for. You say your skimmer is a fair way from the pump and lower than the pump...are there any baffles in your sump? Could you post a picture of your sump? Also, if you have an external pump, and there are any leaks in the plumbing between the sump and the pump it will suck little bits of air in, chop it up, and blow those into the display...which sucks.

Mindy is bang on with the external plumping point, look the words right out of my mouth.

Any random salt creep developing around these points is also a good indication of a plumbing leak.

so i dunno what happened but I went and bought some coral snow
First day i didnt notice a change, second day, no change, today i woke up and almost walked through the tank because i didnt see there was water in it! holy moly this is clear all of a sudden.

freakishly clear.
so what else should i be using with coral snow? sponge power? even with no sponges?

o just to add, the particles were the poop from my tangs after they ate sheets of nori
so i stopped feeding nori everyday, just couple times a week.

the cloudyness was cleared up by the coral snow i believe.

I use coral vitalizer with my coral snow, after about 10 days of use you should see an increase in coral coloration (at least I did).