1 yr serve cough, no test done for gerd 1mo treated 4 better, now cough up a lot of black pecks is that normal. should i get test for sererty of it?

Yes: Coughing up black specks is not normal, unless you wear a lot of black eyeliner! the reflux is not unusual, especially if a month of treatment helped (not specific re the treatment, often you have to use 2times a day proton pump inhibitors). However, the black specks make me worrry re blood, exposure to ? Extraneous material w/ inhalation, or even mold(so called abpa). I would see a lung doc.

Need further testing: Coughing up black specks is a sign of coughing up done old blood , i would encourage immediate testing - a chest x-ray and ct scan.