You don't partake, I gather? Because, let me tell you, none of smokers worry about weed being too strong. Ever. It's not a problem. You see, the time between a puff and onset of the effects is measured in seconds, far shorter than it takes you to smoke a whole joint. If the weed is too strong, you'll know it right away and then just can just, you know, stop. It's not like when you take a pill, or inject yourself and then have no way to undo if the drug is too strong. You just smoke less of it.