Quote:
Originally Posted by sphelps
I'd agree that six years would be a reasonable estimate at this time. That being said with the current design of LED fixtures the energy savings will likely never give a payback if you have to essentially replace the fixture every 6 years. That's without my concerns of premature failure which seems fairly likely with what I've seen with current fixtures on the market and the lack of a decent warranty period on newer fixtures.
On the topic of par vs spectrum I don't believe you're correct, just because the spectrum of the bulb changes doesn't mean the par will also change. Certain halide bulb and ballast combinations will last far past the year mark in terms of par while spectrum is a separate issue.
http://reefkeeping.com/issues/2007-04/ac/index.php
I see LED taking more of a role in supplemental lighting in combination with halides or some other type of HID lighting of the future. |
PAR decreases as spectrum shift due to a few factors. PAR is a measure of Photosynthetically Active Radiation as bulbs shift in color they generally move either towards the right of the spectrum graph or the left, most bulbs we know move towards the right as can be seen in high kelvin bulbs as they go from blue to white-ish. As this happens PAR values drop as the spectrum is now shifting and you get less of both red/blue spectrum that most corals utilize. The point is even if the PAR is still high enough the corals no longer get there needed spectrum so there colors become dull or brown and none of us like that
