2001 Other Hyundai Models Alternator Drive Belt

I just installed another alternator and alternator drive belt. I found the tensioner bolt and was able to tighten the belt but I think I have it too tight because it is squealing at the alternator. I could not loosen the belt to see if the noise goes away. I hope this alternator is not bad. I added some belt dressing and it went away until my engine revved to 2500 rpm then it came back. At a cruising speed at 2000 rpm it was fine. As it sat overnight, the noise came back again and gets louder as rpm's increase. I could have bad bearings in that alternator, but I really think the belt is too tight.

Questions: How do I loosen the alternator drive belt and how tight should the belt be (snug, 1" play, tight)?