Thanks everyone
psfred-good instructions now that I saw how to do it. My apparent problem was early water pump decline(rough when turning the shaft) and another pulley was bent and not tightened properly. After both replaced the belt still squeaked slightly so I replaced it also with good result( told it was a bit "dry".)
I think most of the techs used belt dressing more as a diagnostic aid. My opinion is that the belt slipped for other reasons than just being dry.
Also my tensioner does not have the marks on it like shown in the shop manuals-aftermarket or a label that fell off?