Conditional Formatting: formula results "" counting as greater than x

Hi,
I want to conditional format to highlight values greater than x (in this case 1:59). My formula intentionally blanks out certain rows which should be disregarded (""). These "" cells are being highlighted. It seems the "" cells are counted as infinitely high numbers ("less than" anything does not highlight them). How can I highlight only the non-blank cells that are greater than a given value?
Thank you!
(p.s. please disregard those columns to the left, I have a garbage data source and have to use cleaner columns)