In aquaculture, the feeding costs represent around 30-40% of the total production costs. Therefore some sort of action to rationalize this production aspect could bring significant economic improvements. Although many fish farmers know the meaning and purpose of the feed conversion monitoring, many of them neglect to keep it in check and by doing so they lose serious opportunities of bigger profits which could be obtained with a better rationalization of this process. This article aims to help farmers and technicians to become more aware of the instruments available to them to monitor the feed conversion and to restate its great economic importance. An overview of methods together with some instruction to make a quicker and frequent check of DGR and FCR curves are described in the present article.