If you get any of the three lights below, you’ll have the actual (rather than claimed) light output measurements at various distances, so you can dose accurately. (Note: I’ve already done this for you, so all you have to do is follow my dosing guidelines—you don’t need to do any calculations or measure light output or anything complicated.) But if you decide to get a different light other than what I recommend, you will want to buy a PAR meter and test your device to get measurements of the actual output and dose accurately.
