Where Da Gold At?
In 2008 on CardRunners a poker player with the handle Nutedawg released a MSNL video called "Where Da Gold At" that changed my perspective on preflop play. One of the concepts that he talked about was that when a bad player is in the blinds, you should open up your range from EP to the CO so that you can get in more pots with them. Against weak players with weak ranges in position, we have a lot more steal equity and/or showdown equity than normal. However, in my experiences opening up lighter than my normal ranges has not yielded a profit.
You can tell whether a certain part of your range is yielding profit by going in HEM and using their filter feature. If you have any questions about how to do this, feel free to ask me questions. The filter I set up was for opening wider than my standard ranges from EP-CO. For reference my standard range from EP is AJ+, KQ, 66+, and suited broadways. From MP my standard range is pretty much the same, but I'll open up AT and 22-55 more often. From the CO my standard range is A9+, KT+, QT, JT, 22+, Axs+, K9s+, Q9s+, J8s+, 76s+. I would recommend you take some time running these filters so that you can figure out what works for you.
While Nutedawg's advice might be good or great for mid stakes no limit, there are a few factors working against us at the low stakes. For one thing, it's very common to have two weaker players at each 6-9 handed game if you are doing a good job table selecting. Since your standard ranges from each position should be based on the games you play in, most of the time they are going to factor in that there are some weaker players in the game with you. Maybe taking the reverse approach is the way to look at it - tightening up our ranges when there aren't weaker players behind us.
One of the issues with opening up a weaker hand than normal without the button is that if the pot ends up going three ways, a lot of our advantage goes away. Our steal equity goes way down postflop, and our hand is weaker so we don't have that much showdown equity. *In addition you have to deal with the rake which is a bigger factor in SSNL than MSNL. Since you're really hoping for a heads up pot with the fish, having only one weaker player in the mix would be ideal.
My advice would be to have fixed ranges from each position based on the average games you play in. Your energy is better off spent focusing on other decisions or adding more tables.