Guys, don´t bother "balancing" your ranges anywhere below 200NL and even there you should only do it vs a person who can read your hand (those are few!)
The idea of balancing simply means to have a range made up of different kinds of hands, for the sake of being less "readable" and to gain from a game-theory pov (if u haven´t yet, read
this)
This whole balancing thing plays on the second level, so as long the villain is only concerned about his cards and which button to click on, you´ll actually own urself. Also note, that it´s all about, what the villain perceives to be your range, so u could flip it upside down and exploit a villain who perceives u to be balanced by being not.
For example, I 3bet a 20/16 CO´s open in position. On level one, I´d 3bet all those hands, which happen to have 50% equity+ vs his range when called. "Balancing" would mean, that I add hands like A4s or 56s to that range, which don´t play particularly well vs his continuing range, but are part of a range which is perceived to be at least moderately strong and can gain a profit from folding equity. After 1k hands vs me he looks at his HUD and thinks "OMG hes 3ballin me 10% in position, thats not that strong a range" and has to adjust his former call 3bet/4ball ranges. Until he properly adjusts, we gained a lot from the mistakes he made, due to us being balanced, ie not calling a hand like KQs or AQo, not 4balling JJ or whatever it may be.
"Merging" a range refers to having ur range made up of hands, that are located on a steady interval over ur pot equity (??) {88+,KQo, KJs+, AQ, AK} would be a merged range to say 3bet from the blinds, opposed to a "polarized" range, which looks like {QQ+, AK, 22-44, A2s-A5s}.
We merge our range, to have more hands for value, we polarize a range to gain folding equity on the weak part and stimulate action for the stronger ones in that range.