I'm ole school in my 50x30 red iron framed metal building shop...ceilings 19+ feet
Installed 12 flourescent fixtures using two T5 bulbs..so 24 54 watt bulbs
All the light I need...cheap to operate...shop built in 2014
Link is good place to buy any type bulbs/lamps
https://www.1000bulbs.com/product/90192/USH-3000397.html