I've just been looking at Hartley 2 tonight.
With the Moon only just past 'full', and getting closer to Hartley by the day... (night

) It's getting very difficult to pick out from the background sky.
I was just able to discern it using a mounted pair of 70mm binoculars, and a couple of astronomer's tricks (averted vision, and tapping the tripod)
To be honest, unless you have some big binocs, or a widefield telescope of 4" diameter of more, I wouldn't bother until Halloween night.
Over the next few days, the Moon will pass very close to the comet as they both pass through Gemini - and glare it out even more than it's doing tonight.
Come Halloween night though - the Moon will be out of the way, and the return to GMT will mean that Hartley is at a reasonable height for viewing by 11pm or so.
The link below is a pic I just knocked up by adding a few notations to a screengrab from 'starry Night Pro' software.
Looking East/Southeast - It shows Hartley's approx position at about 1am-2am tonight
And also - in red - it's position at about Midnight on Halloween.
If you want to see it, try to catch it within about a fortnight of Halloween, as it drops down through Canis Minor and Monoceros. By Mid November the Moon will be back big and bright, spoiling the view - and by the time the Moon is out of the way again, in early December, Hartley will be low to the South, around 3am-ish (to the left of Sirius) and fading fast.
Position of Hartley 2