Take the cap off your RDA.
Make sure the wicks are nicely saturated, but NOT NOT NOT flooded. The ideal amount of liquid.. or rather, the maximum, is just a HAIR more than the wicks can hold. If there is a major puddle, there is too much liquid and it'll be harsh, or the flavor will suffer.
Now. Fire the mod.
Me personally, when Im in doubt and checking for what Im telling you to check for, I like to be able to count to 15 while firing the device. Not mississippi-ily, just a steady count to 15. If I can do that, and the entire time all Im seeing is vapor being produced, and NO orange/red coils anywhere, Im happy.
What I suspect, especially because you're using 0mg, is either your flooding the coils, or you're getting a small hot leg during the vape. If its slight, you'll see it, but when you're just vaping you might not be able to tell its a hot leg. A bad hot leg, you can DEFINITELY tell. But a slight one will just come off as a harsh vape.
I would bet one of these two things is happening.
If its the flooding.. simple. Drip less juice.
IF its the hot leg, which is common on the Omega until you get comfortable with it, try tightening up the screws a little, see if that takes care of it. IF not, time to rebuild.
While the wicks are saturated, you should never see ANY glowing coil, anywhere. Also, if you're using cotton, don't get carried away with lighting up that hot leg, it can burn the cotton. If using Silica or Ekowool, burn away, the wicks won't burn on you.
Edit to add- I will say, I personally REALLY like the Omega, its one of my favorites and I have a lot of RDAs. But, as far as ease of use, the Omega is on the harder side. Once you tame it, its a great atomizer, which can produce some fog, and never skimps on flavor.
The idea behind the airhole placement, is that you can "float" the coil above the airhole, and pack the rest of the deck with wick, and get a setup where the airflow comes from underneath the coils. This is commonly agreed upon to produce big flavor. Ala Kayfun, Immortalizer, and other bottom airdraw flavour hounds.
