Need some help choosing LED colors

[Ace25]

Cfl/t5 put off a lot higher par numbers a new cfl at 4" has 600+ par and this is with cheap walmart lamps. T5 at 2" is more like 800+ been a wwhile since I've done par meter tests but leds are much less unless u put them close together and use optics even then my leds over my yank only run like 400 at water surface but at corals its 300-350 sand bed is 250 not a lot of drop off through water unlke other lights. With leds anything over 400 and corals bleach MH/T5 the numbers are much higher. There's been a lot of testing In our local reef club who has an apogee par meter the $350 one. I'm guessing that the reason for your display algae is that you have more par in your tank then with your scrubber. Adding more leds should fix this which is why I'm wondering how much spacing and if your using optics. I'm looking to build a led scrubber also but my cfl one works so good hard to switch especially since leds are all just testing and I have yet to see anyone mention any par numbers with any scrubber. On a side note a cfl bulb after 3 months drops down to 50-75 par from 600+

First, NO optics on LED lights for scrubbers unless your mounting the LEDs 12" inches away from the screen (which I have not heard of anyone doing, but I guess it is always possible). Second, are you just taking someone elses words on what your saying? Reason I ask is because I do own that PAR meter, and have spent the last 10 years testing various lights, and what your claiming is 100% false. I will even post pictures to prove it. And 3rd, you state you have not seen anyone mention PAR numbers, yet, I have posted PAR numbers numerous times on this site and others, so you're not looking very hard to find them.

400w XM 10k MH bulb @ 14"


144w DIY LED fixture @ 14" (over 2x the output of the MH and less that 1/2 the power consumption)


Santa Monica 100 T5HO fixture w/ 2700k lights


26w CFL Spotlight

[gmoney243]

Yes I did the testing myself. That diy led is most likely on a heatsink and the leds are close together yes? All the fixtures I see these days are built with alluminum c-channel including the one I built. The leds are spaced out further which gives high light and uses less leds. I didn't say you couldn't get leds to bake your corals at 1800 par. I said I haven't seen those par numbers listed for any scrubber fixture. Also the 26w cfl you show us a floodlight style. Those suck u get much nore par using spiral with cheap clamp light especially with new feeding guidelines u only want like a 7x7 spread. So the lowes 8" reflectors are to big imo and don't reflect worth crap. I'm not trying to start fight bro just trying to learn and do what I can to help. Back to the point even if your led fixture gets 1800 par what are your corals getting. And still I didn't see any pics of par on led scrubber so I'm still saying if u got algae growing u need more par on ur led scrubber most likely.

[Ace25]

My scrubber light, I just took PAR readings right this minute, gets 300-400 PAR at the screen, BUT it is getting that PAR at exactly the right spectrums needed for photosynthesis (660nm and 455nm).



CFL spotlights are CFL curly bulbs inside a reflector and they get the same PAR readings from my testing. Seriously, not even a 10 PAR difference from my testing using similar wattage. This is why I run 42w CFLs on my other scrubber with reflectors, I have not found any 42w CFL floodlights and you need to get 800+ PAR to even think of coming close to what 200 PAR of correct spectrum LED light will give in terms of growth.

On my display, the corals get variable PAR. You see, when I think about lighting a reef tank, I think of how to best duplicate nature. In nature, the surface of the water gets 2000+ PAR at the highest point. With my old lighting (T5s + MH) I used multiple timers to do the best I could duplicating a ramp up and down in lighting intensity, with LEDs, I can mimic nature exactly, so my light slowly ramps up via PWM signal, sits at full power (PAR reading pictured above) for 1 hour a day, then ramps down. So at the highest point, my corals on the sand bed, which is 36" below the light, gets around 500 PAR, but only for an hour a day. It was my first LED light I made for a display tank back in 2010 (80% of the LEDs are old Cree XR series) and still using it/working perfect to this day. Yes it is on a heatsink with fans, LEDs are 1.5"x1.75" spacing, 48 total, to cover a 30"x24"x24" display tank (75G).



I wasn't trying to pick a fight either, I just get a little edgy when I see things said that go against what I have personally seen and even posted on this site with pictures. If you have any pictures to back your statements I would love to see them, but without them I am going to have to go with what I have seen and photographed myself.

[gmoney243]

right well thats the whole reason i asked Morgan who was having the algae problems what his spacing was and such. when you leds are so close together the light combines and forms a beam just light how the led flashlights are they take like 10 leds combine them and u get a bright light. my fixture the LED are 3" apart center to center but much closer to the tank 8" from water. how far is your spacing on your led scrubber? and what kind of drivers and MA you running them at? what kind of par are u running at your corals? im guessing that most of the day the scrubber is recieving more par than the rocks/corals. which is why your scrubber keeps algae from growing on the rocks. also of course more oxygen and longer light times helps scrubber too but Morgan was having algae problems so was trying to see if he had any of that info so we could come up with a solution and say ok yea you need more light or say ok something else is wrong. also in nature corals are many more feet underwater than your tank so par at ocean surface doesnt really matter its what they are getting. im sure natural sunlight is different to them than artificial light and can probably handle more since evolution has adapted them to it.

also ill see if i can borrow the par meter from the club and take some pics to show the cfl i use and my led fixture

[Ace25]

LED scrubber spacing is 2" apart. I use 1 Meanwell LPC-35-700 to run 14 LEDs @ 700mA on the scrubber. My LED scrubber light is on 9 hrs a day, off 18, my display light is on from 9am-10pm in some form, although first and last 3 hours are very low lighting. Oh, and back on the CFL thing, forgot to mention, the floodlight is = to a CFL + 5" reflector, I didn't test an 8" reflector.

I disagree with the statement "corals are many more feet underwater in nature". Actually, the vast majority of the corals we collect are "lagoon" corals, which are in shallow waters, and are actually exposed to air and sunlight during low tides, even SPS corals. Ever wonder why SPS corals ooze slime when taken out of the water, that is their natural protection for low tides (and predators that may feed on them). In low tides when corals are actually out of the water, the slime coating protects their flesh and keeps it moist.

Natural sunlight vs artificial can be different, or like my light, can be almost identical. I have studied light for over 10 years. On top of a simple PAR meter I also have a spectrometer at my disposal so I know what spectrum the sun puts out and at what intensity and I know how to create and LED light that can best mimic that. Sure, there are some shortcomings with LEDs, certain narrow bandwidth spectrums you still can't cover yet, but overall LEDs can come closer to any other lighting out there in terms of duplicating both the intensity and spectrum of the sun for very little power used. Unless you really take the spectrum of the light into account, PAR readings are pretty meaningless, especially when comparing different types of lighting. 100 PAR of LED lighting can exceed 1000 PAR of MH lighting in terms of coral growth if done properly and you focus on the correct spectrums for growth (like for a frag tank). In general though, we like more light for our viewing pleasure, so we add more spectrums to please us which is why LED lights put out much more than 100 PAR. My display tank overall gets much more PAR overall in a given day, talking at least 4-5x more, but since my ATS light is designed to promote algae growth even though it gets lower PAR than the display, algae still finds it a much better living condition.