How long does your 510-T atty lasts?

[Vaptor]

I like my 510-T but find that atty lasts good for 3-4 days and than it don't work as well anymore. I take the spike out, clean the crad out of the coil, clean the burned wick in the spike but the wick never really comes clean anymore so the atty isn't as good as new. I've found new wick is the only answer. 3-4 days seems rather short time for atty so I wonder how long you guys get the wicj in particular.