Ok so basically I crush 10NL and anything lower.
I play like 19/16 and essentially have a massively sexy blue line and a red line that is slightly below zero but not by too too much.

I have recently been playing 20-25NL and some 50NL as well.
All I see on a daily basis is the same nits/regs running 13/10 (or whatever) on the 6 max tables and they just fold every single time I open in position.
However, they call every single time on when they are on the button when I open from CO or anything before that and alot of times I end up just check folding boards that hit their ranges.
I've had to come up with some complicated check raises and massive aggro plays on the turn and river in order to get them to fold top pair, weak kicker -- middle pair, etc... on draw heavy boards.
I've been making crazy plays with pure air and this is hard for a 9-12 tabler like me because it starts hurting my brain when they play back at me.
It sucks because they never give me action OOP and they always seem to 3 bet me with no problem when I'm OOP with hands like AJ, AQ, 9/10 suited but they generally fold to my AA, KK, QQ of course....

Any suggestions on how to beat the nits?
Also, they rarely stack off unless they have premium hands and don't call too light often.
I'm working on improving my red line for now but need feedback.
Thanks
-crypt

Sounds like variance to me.
In any case, 3-bet them to death in position
If they aren't playing back at you, steal their blinds relentlessly
If they really start playing back at you, reduce the gap between your open raising and 4-betting ranges (this will reduce your fold-to-3bet range) and consider 4-bet bluffing IP with the bottom of your opening range -they will never flat your 4-bet
If they are really interfering with your ability to exploit the fish (or they are taking up all of the seats and there are no fish), move to another table.

Open more in position? Bluff more? Don't valuebet as thin?

If you can ever think of what they are doing too much, or not enough, just do the opposite.

Also, if they are nits, they shouldn't really do anything, and you shouldnt be expecting to make loads of money off of them, you just wanna steal small pots, and iso fish, and they won't do anything to get in your way. You are a fisherman and they are rocks, has a rock ever stopped you from fishing?

When my hook catches on to the bottom of the lake and snags on a rock, I have to cut my line and reset my hook! Even if I manage to reel in the rock, its not worth anything. Very annoying. I try not to fish in areas with too many rocks....if you catch my drift...(table selection)

Well, one thing to consider are you betting the same amount with AJ, AQ, 910 suited as you are with AA KK QQ?

If you are betting the same amount with all of those hands then perhaps they are folding because you took up 2 of the 4 kings and they didn't get anything decent to call you with.