DIY LED supplemental lighting?

[_shorty_]

Okay - I've been running a used light fixture I got for cheap (after replacing the bulbs) on my new tank for about 6 months. It's a 4 ft long ~114g display. The fixture is also 4' long. It has 2 x 250W 14K double ended MHs, 4 x power compact supplimental actinic 65W bulbs, and moonlighting LEDs. It's coming up on time to replace those PC bulbs - so I'm considering ripping out the ballasts and bulbs of the 4 PC bulbs and retrofitting LEDs as a replacement to complement the 2 x 250W bulbs.

In addition - I plan to eventually get an Arduino for full controll over the tank as I can develop it: lighting, pump control, dosing, etc. So I would like to purchase LED drivers that I can dim via the controller when I get that.

So... as always, I am looking to do things as cheaply as possible. But many threads are several years old by now, so I'm looking for the latest recommendations/suggestions on parts to buy:

1) LEDs: what colors, color combos, how many would you recommend, how many watts, etc. to replace my current supplimental lighting?
3W cree's still seem to be the staple? (any comparison references of the the cheaper chinese made vs cree?) Anyone played with the cheap 10W LEDs?

2) dimable drivers - one thread I was reading mentioned the meanwell LDD-1000H which seems like a great solution but is a couple years old and semi-hard to find. Is there a newer replacemtent model for this? or a better model in general today?

3) DC Power Supply - I can come up with something here depending on the recommendations I get as far as my total load ends up being - but welcome recommendations on where to find good prices on them.

4) best suppliers?

5) best affordable heatsyncs? suppliers? I made a fixture with 1" square aluminum tubing and some cheap 1W LED ATS lighting I made, and that seemed to work well - but might not be enough for 3W LEDs ? What if I force decent air movement through them? - obvioulsy these are going to fit up into the old PC compartments so I need long and fairly thin form factor.

Thanks in advance. So much to look through on the forums.. and most of them are trying to accomplish the task of not supplimental lighting, but full reef lighting. So any advice is appreciated.

 

[_shorty_]

So - what I'm thinking so far is:
1) 3W LEDs - 4 arrays of 7 LEDs each.
I'm assuming I should do more than just all Royal Blue LEDs - but I don't know what to put in there. So - ultimately: 28 x 3 W LEDs mostly Royal Blue, some other colors potentially mixed in?
The tank is 24" deep - I also don't know what optics would be needed.

2) Drivers: thinking the LDD-700L - 4 of them, one for each array, of course.

3) Meanwell EPP-150. Power supply - 48.0V @ 3.13A should handle 4 arrays.

4) PowerGate is where I found good selection of drivers and powersuppies. - EBAY seems to be a decent place for LEDs...

5) heatsync... Still wondering if the alluminum tubing will work if I force air through it. Maybe double wide, 4 foot long. one end fit through a hole in one end sealed, and a fan on the other end of the fixture, so air is forced to draw through the center of the tubing. ?


Thoughts? advice? recommendations? I'm 100% guessing how many I'll need.. I suppose if I get too much, I can always dim it. I'd like to suppliment a nice blue amount of light into the DT with these.

 

[jdcook72]

Not anywhere near a complete answer, I know, just on my way out the door, but I would reccomend C-channel over tubing. Much more efficient/effective.

 

[zachts]

These are my thoughts for what they are worth to share some of my research and experience.

heatsinks:
1. C-chanell is the most cost effective approach but enclosed in a retrofit you'll need to blow cool outside air across them to keep cool. could be tough in the same fixture as a MH bulb.
2. Rapid LED has some nice predrilled 48" heatsinks that are nice for easy retrofits and may not need the suplemental fan cooling (just some air flow though from somewhere) much pricier than C chanlle but may be worth it to you.
3. Steves LED does nice kits using presuirzing fans on square tube that would be perfect if you are able to mount the fans to draw in outside air and exhast out the end of the fixture. very cost effective.

Optics:
probalby don't need them. depending on heatsink selection they may not fit anyway. but if theirs room you could always add them latter if you seem to need the extra light focust down into the tank. (the PC reflectors should help with this without the need for optics)

Drivers:
LDDs are pretty fantasic, there is an entire thread just about them. and it was reciently confirmed that they actually convert voltage into ouput current which is perfect since it minimizes excess heat and means you can use watt ratings on power supplies to size them. (smaller power supplies) your 48v 3 amp selection would work great and actually you could add 12 leds per driver. but there is minimal loss of efficiency only running 7 per driver (or even just 1or2 for that mater) so this gives you expandability later! there are custom pc boards available for mounting the LDDs now in the big thread on them.

Dimming:
in the interim you could use one of the cheap RGB knob type PWM dimmers off ebay to dim the LDDs manually (their like $10 for 3 channle control) but would need a separate power supply, any old 12v - 24v wall wart would probalby be fine, or a step down converter off ebay runinning on your 48v supply.

LEDs:
This is very subjective but since your keeping your MH for now the color aesthectics debate over whites, red, green and what is best dosen't apply here.

my recomendations are as follows to replace actinic PC bulbs:
ration of 2 410-430nm violet to every 1 royal blue. you could add in some true blue if you wish at maybe 1 for every 3 other blue or violet LEDs but you'll want to dim those separate as they might be a little much. Most PC actinics don't really have any true blue (470-480nm).

Source wise stay FAR, FAR, FAR away from Ebay for your LEDs! look to Rapid LED or Steves LED there products have been great in my experience. Rapids violets can handle a little more heat abuse so might be a better choice, however, Steves LED can make you custom 3up chips using the violets and cheapo royalblues he offers (these 3ups, and violets in general in your application(due to heat in confined space) should not be driven over 500mA though) Royal blues and blues if of the Cree or Luxeon persuasion can run happily at up to 1000mA in most applications. basically violet over 410nm to around 430nm, anything in this range will give you very good flourescent "pop" like your actinics with less blue look to most people. (never use any of the 405nm not needed, spectrum wise, as those are much to close to UVA and your MH will have plenty of that) Royal blue and blue will give a more pronounced blue look, also excellent flourecent "pop"

Hope that doesn't make your brain hurt :lol2: its a lot to ponder........
.....and only a few options to consider!

 

[_shorty_]

Thanks for the info! That is very helpful in getting me started!

First question: what is your reasoning for being able to run 12 LEDs per driver? I didn't follow that.

The drivers i mentioned are 32v x .7A = 3w x #_of_LEDs. Which comes out to like 7.5 LEDs. ? I guess you just wouldn't drive the 12 LEDs at full 3w then is what you're saying? Which might be a good thing based on what you said about temperature constraints?

Second question - total amount of lighting I specked out: is it enough for what I'm trying to accomplish?

 

[_shorty_]

^^
Maybe this should be obvious, but heat generated will be more based on current only? Or will voltage affect this as well. I had to double think my comment in my post...

Also... Why is C channel more effective? I'd think you can force more air flow through the tubing than an open channel.

 

[zachts]

(this started gettin long as I was typing again, sorry but I'm happy to regurgitate what I've learned over the last two years of reading )

To first question:

your right, my brain some how saw LDD-H (which handles up to 56 volts input) you listed LDD-L which actually can not handle the 48 volt input you list, sorry I didn't catch that until now. LDD-L is rated to handle input of 36 volts. good thing you are paying attention something I highly recommend! you would need a lower voltage power supply to run the LDD-L.

LDD-H was my reasoning....... :crazy1: but...
you still could feasable use 10 leds on the LDD-L given 36 volt input and using Luxeon rebel for example which run at 3 volts each at 700mA you'd be pushing the limits there, but should sitll be with in the 32 volt output of the LDD-L. (there are dozens of factors that figure in to how many will be able to run on on driver, but it all comes down to the operating voltage of the LED at the current your driving it at. at 500mA you could most likely run 12 Luxeons on the LDD-L due to the lower voltage at lower current) 7 or 8 LEDs is safe bet but could add more most likely in future given that efficiencies of newer chips are alwasy getting beter. when you narrow down the chip choice you can better determine how many to run per driver.

3 watt rating is subjective and related to actuall drive current and operating voltage. the later varies with factors like heat and drive current so (volts times ampes gets you the actuall watts)

so based on the potentenial temperature constrantes in your retrofit you would not want to run them at max curent and 100% duty cycle, they would likely over heat (700mA is max on all the violets available and only recommended with very good cooling capability unless you are sure you will not run them at 100% duty cylce) but 500mA is a safer bet.

Cree and luxeon chips (every color except violet, they don't make one) are fine at higher currents due to them having higher temperature ratings and much higher current ratings. so 700mA on the luxeons or Cree would be just fine in your setup.

Second Question:

your last sentance in first post, as your only going for supplemental lighting your 28 LEDs will give you plenty. (very general rule of thumb seems to be that about 1/2 to 1/3 the power use can be expected from switching from PC to LED. Due to the more focusused spectrum/directionallity and slightly greater efficiency of LED. you could likely totaly light your tank with LED using only around 48-72 dependingon factors like LED color, type, optics and drive current/heatsink configuration.

 

[zachts]

Your original post went though a lot of questions, which may warrant a more detailed discusison (1-5) if you want........

others will hopefully chime in. Keep reading though, I still find new info and ideas I had not considered before in the various massive LED threads.

 

[_shorty_]

I really appreciate you taking the time to answer questions. I'll keep reading and will probably read your posts once or twice more , and post more questions as they arise.

Oh.. And good call. I'll switch to looking at the LDD-H so I don't run the risk letting the smoke out of my drivers... Thanks again!

 

[_shorty_]

Okay - so as I get more in depth about actual LED selection, based on what you tell me about running most at 500mA instead of 700mA. Here are my wattage calcs that I will base other calcs off of:

Steve's Luxeon Royal Blue is 2.75V @ .7A (max 1000mA) = 2W
Steve's generic Violet is 3.4V @ .7A (max 700mA) linearly interpolated down to .5A = only ~1.25W
Similar story with generic blue is 3.5V @ .7A (max 700mA) interpolated down to .5A = only ~1.3W
Rapid's Luxeon Rebel Blue is 3V @ .7A (max 1000mA) = 2.1W

So most people really reduce violets to run down at ~1.3W-1.5W (i know it's not exact as it won't actually be linear) to keep a longer life span? Is this basically why you are recommending 2 violets per every 1 blue, used?

So is it a general rule of thumb to run LEDs a step lower than max amperage? Is that a true statement to say the only exceptions are in high air flow/well cooled applications?

 

[zachts]

Okay - so as I get more in depth about actual LED selection, based on what you tell me about running most at 500mA instead of 700mA.
Here are my wattage calcs that I will base other calcs off of:

Steve's Luxeon Royal Blue is 2.75V @ .7A (max 1000mA) = 2W
Steve's generic Violet is 3.4V @ .7A (max 700mA) linearly interpolated down to .5A = only ~1.25W
Similar story with generic blue is 3.5V @ .7A (max 700mA) interpolated down to .5A = only ~1.3W
Rapid's Luxeon Rebel Blue is 3V @ .7A (max 1000mA) = 2.1W

So most people really reduce violets to run down at ~1.3W-1.5W (i know it's not exact as it won't actually be linear) to keep a longer life span? Is this basically why you are recommending 2 violets per every 1 blue, used?

Essentially yes, also even at the same drive current violets are much less powerful than the royal blue (when you compare mW of light produced)

So is it a general rule of thumb to run LEDs a step lower than max amperage? Is that a true statement to say the only exceptions are in high air flow/well cooled applications?

the general rule of thumb is ~70% of max rated current. the benifits of running more leds at lower current are lower heat, longer life, and lower voltage(thus greater efficiency) the lower the current the better for the above factors, just means additional LEDs to achieve same light output. It's a ballancing act of upfront cost v.s. efficeincy, and heat generation/operating environment.

See comments above in Bold.

Do you have a way to measure how hot the inside of your PC chamber gets with the MH on? temperature will be a driving factor of this retro fit and the violets will be the limiting LED as they have a maximum operational temperature of 124 degrees farenhieght.

 

[gbru316]

Although violets might seem less powerful than blues for a given drive current, light in the violet wavelengths carries more energy than light in the blue wavelengths.

This energy is more important to coral than the power of the source. Just something to keep in mind.

 

[zachts]

ahh, yes, good point. I had not addressed the visuall differnce, they do apear much dimmer than royal blue. they are more like a black light in that sense, creating flourescence without as much visible light.

however they are also less powerfull from a radiomentric output standpoint (which is what is important to the coral)

best of the best violets output something around 700-800mW @700mA (maxing them out)
steves royal blue luxeon is right around 1100mW @700mA. (outputs up to around 1600mW at max current of 1000mA)

but as gbru points out with each outputing the same mW the violet will look much dimmer to our eyes, but will have a bit more useful photosynthetic effect for the coral (that point has been debated alot so I'd just consider the two equal on that matter)

the gap is getting closer but the market is still driven by royal blue since those are used for making white LEDs and violets basically follow behind the advances in royal blue technology since they have more specialized use.

 

[_shorty_]

Okay...

PLEASE correct me if math or something is off. ANY and all input is more than welcome! But, based off of previous recommendations, here's what I'm thinking so far:

LEDS:
10 x Steve's Luxeon Blue LED's - $2.99 each - 2.75V @ .7A OR ~2V @ .5A
20 x Steve's Violet LED's - $3.40 each - 2.5V @ .5A
4 x Steve's Luxeon True Blue - $3.40 each - 2.2V @ .5A

DRIVERS:
1 x LDD-700L ~$4 each
3 x LDD-500L ~$4 each

PS:
MeanWell EPS-65-24 : 24V @ 2.71A - $15.50

Array 1:
LDD-700L with 8 x Luxeon Blues @ .7A
Arrays 2 & 3:
LDD-500L with 9 x Violets @ .5A
Array 4:
LDD-500L with 4 TrueBlues, 2 Blues , and 2 Violets all @ .5A

2 Dimmer circuits:
1 dimmer circuit for Arrays 1,2, & 3 together;
1 dimmer circuit for array 4 seperately.

Total LED count: 10 BLues, 20 Violets, 4 True Blues.
Total $$ count (not including heat sync, dimmer circuitry, fans, shipping, or extras): $143.00

 

[_shorty_]

in addition - here's what I'm thinking for general layout and cooling. Remember that these are retrofit up into the PC sections my light fixture. 2 Bars, one on either side of the MH fixtures.

I think in this application - the full square tubing is best to be able to force air through the center of the tubing. The C channel is probably more ideal for non-enclosed applications, I'm guessing.

Considering doing double-wide for each bar (two tubes parallel, fastened together) to widen the heat load more... but that'll cost an extra $30ish bucks and un-sure whether it will be needed or not.

 

[chicken]

2) dimable drivers - one thread I was reading mentioned the meanwell LDD-1000H which seems like a great solution but is a couple years old and semi-hard to find. Is there a newer replacemtent model for this? or a better model in general today?

The meanwell LDDs are about 20 months old from my understanding but the reason you cannot find them is everyone on here and a bunch of other reef forums realized they are such great drivers (and cheap) and outstripped the supply of them. I think you should start seeing a bunch of them hitting the various vendors in the next few months so they should be easier to get your hands on. My dealings with them have been extremely positive so far. I am using 22 of them on the build for my 600g tank split across 7 PWM channels to control the color. Good luck with your build.

 

[zachts]

Well......

looking at your sketch I would flip the fan around and get rid of the blocking, use C channel of the 1.25" x .25" type. if you can't find it local this place is rather cheap even with shipping they are cheaper than homedepot for a few pieces for me anyway. http://www.speedymetals.com/pc-2531-8348-1-14-x-1-14-x-18-channel-6063-t52-aluminum-extruded.aspx
this would be my choice I think for cheap and effective. I don't think a normal fan will draw enough air thru the tube to do much good as they really aren't good at creating presure, just blowing low pressure air, plus your fixture probably will leak air and not draw all the air from one end to the other. blowing air in would create better cooling using channel to get more metal surface area to moving air exposure. the square tube really only works when set up like on StevesLED website. If done right though it's a great solution.


If going with square tube this approach used by Steve's LED would be best if you can accomodate the pressureizing fans to draw cool air in thru the top or sides of your hood. there has to be a good seal between the fan and tube. http://shop.stevesleds.com/product.sc?productId=64&categoryId=22
Steve's can walk you thru the process.

 

[_shorty_]

Well......

looking at your sketch I would flip the fan around and get rid of the blocking, use C channel of the 1.25" x .25" type. if you can't find it local this place is rather cheap even with shipping they are cheaper than homedepot for a few pieces for me anyway. http://www.speedymetals.com/pc-2531-8348-1-14-x-1-14-x-18-channel-6063-t52-aluminum-extruded.aspx
this would be my choice I think for cheap and effective. I don't think a normal fan will draw enough air thru the tube to do much good as they really aren't good at creating presure, just blowing low pressure air, plus your fixture probably will leak air and not draw all the air from one end to the other. blowing air in would create better cooling using channel to get more metal surface area to moving air exposure. the square tube really only works when set up like on StevesLED website. If done right though it's a great solution.


If going with square tube this approach used by Steve's LED would be best if you can accomodate the pressureizing fans to draw cool air in thru the top or sides of your hood. there has to be a good seal between the fan and tube. http://shop.stevesleds.com/product.sc?productId=64&categoryId=22
Steve's can walk you thru the process.

thanks. I'll look again at the cooling. What you think of the current choices of LEDs and electronics?

 

[zachts]

your color selection and layout looks good to me.

taking a closer look at your voltage assumptions LEDs really aren't linear for example I just measured some of the Steve's chips I hapend to have laying on my table and :
for the violet @ 350mA I get 3.2v and 3.4 @ 580mA), so...

Steves True Blue I get 3.1v @ 580mA.

Steves Royal Blue I get 2.85v @ 580mA

My recommendation is to use:
3.5v for your violet calcs
3.2v for your True Blue calcs @500mA (still use 3.5 if running them above that)
3.0v for your Royal Blue Calcs. (even though they will probalby be slightly under this)
Just to play it safe, as your dirvers would probalby light things up with 9 violets on a string but they would only be pusing a few dozen mA to accomodate the voltage limitation and would look very very dim. It's better to over estimate voltage a bit as the driver compensates, and in the case of the LDD it does so very eficiently.

you probalby should plan on a higher voltage powersupply 36v would accomodate your setup. but you would have to use LDD-H as 36v would be pushing your LDD-L a bit too much for comfort, IMO

you might consider though using a few more LDD-L and getting each color on its own drivers and control string so that you control each color independantly. that might entail using 6 True Blue or just putting a couple of the Royal Blue on with them. No right or wrong way here, all up to you. I know you are trying to minimize over all costs and componets here. so If you look at your MH spectral graphs I would eliminate the True blue LEDs if you MH has light in that wavelenth (465-480nm)

:beer:

P.S. and way off topic, I just noticed your in Decatur, I rarely get over that way but I'm working on the design of the new penguin exhibit at the Scoville Zoo there!

 

[_shorty_]

Very valuable info. Thanks again!

Also very cool about the penguin exhibit! My wife told me one was going in. We are looking forward to that. Youre more than welcome to stop by and talk reef stuff when in town.