If in your post grid element you have setup Teaser/Excerpt as Text option then it should work just fine with "..." thing.
About length of it go to Blame->Blog, Search & Archives appearance->Type of post excerpts. Now set it to Automatic, change Number of words to cut post and you can set back to Manual if you prefer. Save, and you are done:-)
Comments
If in your post grid element you have setup Teaser/Excerpt as Text option then it should work just fine with "..." thing.
About length of it go to Blame->Blog, Search & Archives appearance->Type of post excerpts. Now set it to Automatic, change Number of words to cut post and you can set back to Manual if you prefer. Save, and you are done:-)
Hope that helps.
With regards.