But is it a close up filter (let's say +10) is the same as an achromat? I might be easier for me to get a close up filter instead of an achromat. I am located in Colombia, and there is no much option down here, and shipping is not that cheap.
An achromat is a closeup filter, but a special kind of lens.
It's is made up of two or more pieces of glass glued together that help correct for distortion inherent in single lens design. Specifically chromatic aberration.
A great source of high quality cheap achromatic lenses (large enough to use) are in binoculars. 50mm lenses are common and cheap. Better are 60mm and 70mm lenses.