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View Full Version : Too much or too little light?

mv123
09/27/2014, 06:42 AM
hi all,

I have a 90 gallon newish reef that is lit by 24 Cree-XPe LEds, 12 are blue and 12 white. I am currently running these all at 50%, and my RBTA, frogspawn, and Bubble coral all seem to be doing well. I would like to add some SPS to the tank soon, but I am having a hard time figuring out what to do with the lights. Should I start ramping up the intensity?

The lights are about 2.5 inches from the water surface, and 20 inches from the gravel. There is a glass water shield over them.

I don't have access to a par meter, so I really don't know how much actual light is getting down to the rocks. I am worried about burning my corals if I crank up the lighting, but on the other hand don't want them to struggle.

Any suggestions from Cree LEd users with SPs tanks?

Thanks!
saltyair
09/27/2014, 06:56 AM
First 2.5 inches from the water is to close - should be 6 to 12 inches off the water, it will give you a better spread of light.
How stable are your alk, cal and mag?
mv123
09/27/2014, 07:16 AM
Height over the tank is not really subject to change because the lights are in an Elos Aquatop which sits on the tank top and has glass lids on the front and back. Great because it keeps my wrasses from jumping to the floor, but maybe not ideal for lighting.

Water parameters are fine and stable. I have lots of experience with SPS in previous tanks, but those were all running either Metal Halide or VHOs (I know, VHOs, I'm dating myself!)

thanks
mv123
09/27/2014, 05:37 PM
Bump, any led owners have any thoughts?
mv123
09/28/2014, 09:08 PM
Bump again...anyone? :-(
scubadan206
10/01/2014, 11:07 AM
I have seen Radion users bump up to 100%. Radion's use Cree LED's. Again, most or all would be set at 8 inch plus height. LED's have a laser beam like effect at too close a distance. The light NEEDS to be dispersed. [Kessil does this well.] You would probably burn out the very close corals, and starve out the lower corals at the same time. That's one of the secrets of using LED's IMO.
Find a way to elevate them, and you can probably acclimate your corals to any intensity you want to run.

Daniel. :wildone: