"While Echo of Light does not stack, the nature of the effect allows each proc to contribute to a 'reservoir' of healing to be granted to the target. Each subsequent proc adds its contribution to the amount still remaining to be granted to the target, and a fresh buff for the new total amount is created, to be granted over a fresh 6 second period. In this way, Echo of Light's design ensures that no bonus healing is wasted. Repeated heals to a target over a sufficiently short period of time will therefore steadily increase the HPS and amount per tick granted by the target's Echo of Light buff."
Please go away troll.