I’ve been doing some research on LED lighting using high power (>1W) LED. It seem the preferred method for “dimming” is through Pulse width modulation (PWM) if I understand it correctly the LEDs are not being dimmed but rather being turned on or off at a rate that makes them appear to be dimmer. I’m assuming that these frequencies are designed for humans, does anybody know of where I can get more information on the affects of PWM on reef systems?