Originally Posted by JJ-MIK
I have a question.. It's probably a simple answer... What's the difference between led
when it comes to running them . My thought is. Why do you accent blue with mh
.. And with led
. You accent white? 50% white to 100% blue.. If I turn of my blues. The tank is very dimly lit.. Just wondering..
The metal halides that don't really need blue supplement are the ones with a color temp upwards of 20k. These far bluer lamps have a lot less PAR than the lower K
, so what people do is use a lamp that is 10-14k, which give much higher PAR, and then accent with blue lamps to make the tank more pleasing to the eye. Otherwise the tank and corals are going to look bright, but dull.
LEDs, being much more efficient, can deliver an amazing amount of PAR with blue lamps, but you don't want the tank looking solid blue, or it won't be aesthetically pleasing either, so we have to throw in some white to offset it, and give a more natural look.
Originally Posted by jeffaquarius
By comparing them MH
requires much more power than LED
to attain the same amount of PUR. MH
is less efficient and radiates light at 360 deg while LED
is unidirectional and can be zoomed in with low angle lenses to penetrate deeper. MH
is full spectrum so it does waste a lot of light energy while LED
uses only the right frequency or color (blue) with some whites to please our eyes. For those with MH
and add blue LEDs, I believe they use the LEDs for moonlight. Otherwise, it is just aesthetic to have more blues.
Well said. And don't forget the totally undesirable by product of halides- heat. So much heat that touching a warmed up lamp can burn the skin right off your hand.