Shop light fixtures are usually T8, which is a different bulb diameter and ballast. T5's put out more light intensity than t8's, and likewise t5ho's more than t5's.
Shop lights also have very basic reflectors on them, usually just a flat white. A high quality plant light will have a mirror like reflector on it, which also results in a higher light intensity since it's being focused better.
Switching from a basic t8 dual shop light setup to even a cheap t5ho (only about double the price, $40-50) is a dramatic difference.
This is far less of an issue with a non planted tank, though, and in my non planted or low light tanks I run t8 shop lights rather than T5hos.
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