I'm posting my recent experience with making the LED switch. I will preface by saying I have no LED experience prior to 4 weeks ago. I have followed the forums and read about AI, Ecotech etc... I have pretty good experience with all types of MH lighting. So when I went to LED I figured that nothing could be brighter than my MH. I was using 250W DE Phoenix 14K on CV electronic ballasts. I had 750W over 6 ft tank. My sps had slow but steady growth for 2.5yrs. The MH pendants were 6" off water in a tank 24" deep with most of my acros near surface.
I purchased 3 Orphek PR156 based on a number of reviews. I got the 90 degree optics for more focused light since I had direct light on my corals from the MH pendants.
I can not believe the intensity of these LED fixtures!! I have read that surface PAR/PUR is ~1000+ at 18" above water( but didn't believe it apparently) I placed them ~15" above the water( as much as my canopy could allow). After a day or so I realized how much more intense this lighting is. My acros near surface bleached ( more like BURNED)their tips. I reduced the daily light cycle from 6 hrs to 4hrs and still was too much. I bought some screening at Lowes. 18x37" expandable window screens (~$7 @). This seems to have reduced the light to where my 250W MH was previously.
My recommendations:
1. If switching from MH to LEDs consider the optics and dimmable cababilities of the LEDs( like Orphek nilus). It may be better to choose a system that has wider coverage 120 deg vs 90 deg and dimmable especially for a tank = or <24"depth( maybe AI or Ecotech) Intense, focused light may not be the best option.
2. Reduce photoperiod and increase gradually over weeks
3. Use screening irregardless of how the light looks especially if the LEDs have higher UV output like the Orpheks.
4. Watch your corals very closely over the first fews weeks at different times in your light cycle to see how they are reacting to the change. Adjust accordingly with screening. Some have recommended multiple layers of screen peeling off a layer every 4-5days until full light intensity achieved. I'm still working on this.
On a positive note some of my corals have taken off growing especially chalices near bottom. The colors are better in some corals and the blue moonlight effect is amazing.
Sig
I purchased 3 Orphek PR156 based on a number of reviews. I got the 90 degree optics for more focused light since I had direct light on my corals from the MH pendants.
I can not believe the intensity of these LED fixtures!! I have read that surface PAR/PUR is ~1000+ at 18" above water( but didn't believe it apparently) I placed them ~15" above the water( as much as my canopy could allow). After a day or so I realized how much more intense this lighting is. My acros near surface bleached ( more like BURNED)their tips. I reduced the daily light cycle from 6 hrs to 4hrs and still was too much. I bought some screening at Lowes. 18x37" expandable window screens (~$7 @). This seems to have reduced the light to where my 250W MH was previously.
My recommendations:
1. If switching from MH to LEDs consider the optics and dimmable cababilities of the LEDs( like Orphek nilus). It may be better to choose a system that has wider coverage 120 deg vs 90 deg and dimmable especially for a tank = or <24"depth( maybe AI or Ecotech) Intense, focused light may not be the best option.
2. Reduce photoperiod and increase gradually over weeks
3. Use screening irregardless of how the light looks especially if the LEDs have higher UV output like the Orpheks.
4. Watch your corals very closely over the first fews weeks at different times in your light cycle to see how they are reacting to the change. Adjust accordingly with screening. Some have recommended multiple layers of screen peeling off a layer every 4-5days until full light intensity achieved. I'm still working on this.
On a positive note some of my corals have taken off growing especially chalices near bottom. The colors are better in some corals and the blue moonlight effect is amazing.
Sig
