slightly a distortion of waveform and the percentage of total har-monic current distortion (%THDi) has a value less than that of thefluorescent T8 lamp with both types of ballast (electromagnetic andelectronic ballast); this is because the brands E and P of electronicballasts are more effectively designed and more expensive. Con-sequently, the fluorescent T5 tube lamp functioning with brandB electronic ballast will be considered as example of harmonicssource in electrical network and focused for harmonic reductionowing to its most harmonics generation. Hence, this paper tries todesign a passive harmonic filter for brand B and put it in the systemin order to reduce the produced harmonics whose the magnitudeis higher than the considered standard level