Being in the Austin hill country in a brand new home myself (8 months old) I had to deal with bugs as well (I also had the issue of scorpions in the house on mult. occasions).
I chose to use an all purpose killer that was the only known pesticide that kills scorpions as well.
It's called CY-KICK CS and can be found at most chemical supply shops (like self-chem).
the ~$45 bottle lasts a really long time. I spray about once a month and haven't seen a spider/ant/scorpion in my house in a long time.
I take care to cover my tank and turn off the skimmer if I spray inside (which i've only done once since external spraying seems to be doing the trick).


MSDS: http://www.wmmg.com/pdf/msds/CyKickCS_MSDS_R5.pdf