redneck,
That was actually a sincere post. You didn't mention the time of year and temperatures, only RH outside. I suppose that I associate the Gulf Coast with warm temps.
At any rate, if the highs were 60 degrees, you were probably running heat inside, and the indoor humidity was still lower than outside. Use that valuable digital meter to check indoor RH if in doubt.
If I had consistent high ambient RH, I'd try 100% PG (without the water) and see how it maintains. It's possible that it would absorb moisture to maintain the desired 70%. If not, the 50/50 should work, and when it stops holding it down, put the (de)humidifier in the fridge for a few days to dry it out.
- Mr. 0