Black box light question

[Noobreefer90]

Ok so I ordered this light 

phlizon 165w dimmable full spectrum aquarium led because my led coral light I had fell into my tank. Just added the light to my tank last night. Corals seem to like it. My corals with 6 days before with only a cheap led. I have the fixture 13” above the water. I have the whites on 40-50%. Blues. 50-60%.  Anyone else have black box what’s your settings at. I don’t want to rish bleaching my corals my nem was alrdy bleached some. Because I put the light only 6” 

[seabass]

If your old light was weaker, I'd dim it a bit more, then slooowly turn it up a bit each week until you get it to where you want it.

[Chris's Fishes]

If you're worried about it, definitely dim it down a bit at first. I almost lost an RFA to too much light when I got my black box.

 

On my 20 long, I have a Wattshine 140W running 100% on both whites and blues. I'd call the lighting on the upper side of medium light - and I'm getting a second one for full tank coverage. There's quite a bit of variation in black boxes when it comes to power, so I'd get the light, start it pretty dim, and slowly increase it to where you think looks best. 

 

Also, you may want to consider removing the optics on your fixture, if you find that the light looks a bit odd or that you're getting a narrow spread. I did on mine, and easily like the light 4 or 5 times more than I did before. The light is less purple/red than it was before, and looks more like proper lighting, even on the same settings. Better spread, too.

[mcarroll]

I agree:  Don't hesitate to dim the fixture more.   Get a lux meter app (at the very least...handheld meters are only around $10) to check it, but all you need at the water surface is >10,000-15,000 lux.  >30,000 if you're shooting for clams or other high-light critters.

 

Lower the fixture back down to the height where you want it too since you have dimming.  Little or no light-spill outside the tank would be ideal. 

 

For reference, if it has 90degree lenses then at the current 13" mounting height, you're blasting the tank with >26" in diameter coverage of light.  If they're 120degree lenses, then the coverage diameter would be proportionately even larger. 

 

So at 13" mounting height, that's a lot of potentially wasted light (and a lot of light pollution in your room) if you're running a fairly small tank.