LED novice needs some help

[jtl]

I currently have a 48x24x20 tank with 8 Par38 LEDs. These are the Nanotuner ones that have five 3-w leds per lamp. I have 4 that have 2 royal blue and 3 cool white and 4 that have 3 royal blue and 2 cool white. They have 40 degree optics and are mounted at 33" face of lamp to the sand. The coverage is good but I am not happy with the color and my corals are doing ok, but not great. I would like to supplement my existing light with some thing to balance out the colors and give me more blue tones to enhance the colors of the corals.

I think a solution is to add additional leds and maybe even cut back on the Par 38's. I am considering getting two 4.23 x 16 pre-drilled and tapped heat sinks and work up some combination of leds. The heat sinks can accomodate 24 leds each but if I use any or all of my existing lamps it may be over kill and a waste of money. Initially I thought of just copying the combination that AI uses in their blue SOL unit since I know a couple of people who rave about them. I am really open to suggestions of what might work but at a minimum I want to be able to dim and change the color temp. Thanks
John

 

[Onedesign1]

well...the issue I see is that you have the Par 38s already there...putting heatsinks under them will render them useless and those 2 heatsinks with 48 LEDs alone will be light on coverage. On my 4x2x2 tank I have 77 LEDs....60 would be the lower limit IMO. I know that leaves you starting from scratch so to speak but I feel that would be the best approach. However if you feel you could arrange a DIY fixture around those 38's then maybe you could make something work nut even then you wouldn't have full control as you indicate you would like. Give it some thought and ask away.

 

[jtl]

Maybe I am missing something here. I have 40 leds on my par 38 fixtures and now I am considering an additional 48 leds which is 88 leds. This is just supplemental lighting to enhance some color issues. The coral growth is not bad, in fact the zoas are going crazy. I was just looking for some ideas on mixing colors to bring out the reds and blues.

 

[Onedesign1]

I'm just saying how do you physically arrange them with 8 large floods already over the tank?

 

[jtl]

Now I get it. The Par 38's are in two rows and there is sufficient room between the rows to add the panels of leds. I just have to keep the new leds slighty higher than the bottom of the Par 38 lamps so that they can still be moved around for spot lighting certain areas that may need additional light. As far as coverage goes i agree that 48 leds alone is on the weak end but interestingly the AI fixtures each have 24 leds and a friend of mine had one fixture over a 30x30 cube and his corals were doing fantastic. They use Cree leds but maybe the optics are unique. I just figured that since I already have the Par 38 lamps and they are doing pretty good I would just kick it up a notch and add some more color variation. I am not getting the atinic to make certain colors pop and while a lot of the zoas are doing fine some of the other corals could use some help. Since my friends tank was doing so well with the AI fixture and he had very high end stuff I figured I would just copy that lighting plan. The AI fixture arranges the leds in pods of 3 but since I am considering a pre-drilled heat sink I am stuck with lining them up in rows.

 

[Onedesign1]

ok I see now too!

The AI do not use special optics...just pretty tight at 40 degree but they are customizable anyhow. The pods are draw backs IMO...basically you have spot lights on a small foot print. Spreading them evenly as you describe are the way most DIY are done and it provides terrific coverage.

So it sounds like you think your spots are doing a decent job but you want more light and color. So maybe those 2 heatsinks with 16 on each one would be a good start. Say 10 royal blues, a couple greens, and 4 neutral whites on each one. You could do it with 1 ELN 48 on each heatsink too. Just thinking out loud.

 

[jtl]

That is a thought but can I really put 16 leds on one ELN. I also posted questions on another forum that you frequent reqarding things like using a Dim 4 vs getting a module for my existing Reefkeeper lite. Look forward to your suggestions.

 

[Onedesign1]

hmm...which forum? I don't recall seeing those questions on the DIM4. You in my neighborhood on BARS?

Yes you can run 16 off a single ELN by running 2 parallel strings of 8. I have done up to 28 on a single ELN for a friend as an actinic supplement bar with his T5s over a 150 tall and its been running great for about a year. They're running about 650ma.

 

[jtl]

Led to supplement Par38 in RC-DYI.

Isn't it risky to run leds in parallel, I am by no means an electronics wizard.

 

[Onedesign1]

no its not risky...you use fuses to protect the strings. Its the only way to do large builds without a bunch of individual drivers.

The DIM4 can run 3 or 4 LEDs per channel at 500ma. Not sure about the Reefkeeper modules. Also can't find any thread with that subject in RC

 

[jtl]

75g Tank Build :: RadionSettings.mp4 video by rockyrubicon - Photobucket

This is an interesting comparison of colors, maybe you have seen it.

Here is my thread in RC, I see I made a typo in the title.
LED to suplement Par 38 - Reef Central Online Community

 

[ReefLEDLights]

Isn't it risky to run leds in parallel, I am by no means an electronics wizard.

info on running strings for you.
Wiring Diagrams « « ReefLEDLights | LED Aquarium Lighting ReefLEDLights | LED Aquarium Lighting

 

[jtl]

I think I mentioned that electronics is not my strong suit. I want to control three separate strings of leds in series. One will have 13, although I have been told I could have 14 (?). What would be the ELN, P or D? Is this a better way to go than adding a module to my RKL?

 

[CJO]

The number of LEDs you can run in series depends on the voltage of the driver and the forward voltage of the LEDs you are using.

The Meanwell ELN 60-48D is a commonly used driver that puts out a constant 48 volts. The D means that it is dimmable and the dimming is compatible with the Reef Keeper controllers. I don't know whether you need a separate module for the RKL to do this or not.
CJ