DIY LED Array build

[Santoki]

I think with how active these threads have become, it is very easy for an unanswered question to get lost...
chriscobb,
Whether the heat emitted from your MH setup will have a negative impact on your LEDs will be dependent on how close they are to each other.
Just keep LED junction temps below 80˚C or 176˚F.
-R

 

[chriscobb]

Thanks!!!

 

[daytriper]

Hi I have been reading this thread and I have a 180 tank that leaks so I have to take it down and replace with a 90 gallon. That being said, my wife has suggested that we re purpose this tank as my coffin. I said only if bury me nude. I would like to build an LED array, 36 inches by 12 inches with 36 cool white and royal blue LED's. These would be spaced 4 inches length wise and 2.5 inches across, staggered, with no lenses. I would like to do like Menthol did on his array. This tank would have mixed LSP, SSP and zoos and leathers. The tank is 18 inches deep, 18 inches wide and 4 foot long. I know that leaves a gap on all 4 sides. I would like to build this as cheaply as possible using Q5's....Suggestions Please ...Note my electronics experience is ancient and I haven't used it for years. Thank You For Your Time

 

[der_wille_zur_macht]

36 cool white and royal blue LED's.

Do you mean 36 of each, or 36 alltogether?

 

[daytriper]

36 total like menhol he seems to have good growth.

 

[der_wille_zur_macht]

36 total on a 90 is gonna be pretty weak IMHO. FWIW Soundwave's original build was 48 on a 75, and by most people's standards, even that is a hair on the low side. 36 might be appropriate for something in the 40 - 50 gallon range, IMHO you'd be happier with 50 - 60 on a 90.

But of course it depends on your goals, and how you design the build. If you only had one or two main rock piles in a 90, you could position the 36 LEDs around those and be just fine.

 

[daytriper]

I might go with 48 or more if I can find some cheap way of driving them and the forums have so much info that I am stuck on what is the best way to do so. You seem to have endless ideals on led arrays and as fascinating as this may be it is equally as confusing. Thank you for your time once again.

 

[Reef_Matrix29]

48 LEDs on a 90 gallon would work good with 60 degree optics and at least 12" mount height....the question will be what to drive them at, I would start at 500mA and check with a PAR meter. If you don't have one available to you, I would use a crude way of photo-documenting them week by week and slowly ramp up the current until you see distress and then back it back down. But I would suggest doing 100mA increases after 2 weeks to get a more accurate display of the LEDs effects, IMO.

 

[daytriper]

So how to drive them I am willing to change resisters to increase or decrease power but what is the easiest way and cheapest way to do so?

 

[deral]

Can I mount LED at 1" height? Do I need optics?

 

[schnitm]

Thanks for the info Kcress.....Can anyone comment on if people are still using the XRE Q5 or are people using the XPG's?

I've experimented with XPGs and will be using them. I decided to go with 1 XPG cool white for 2 XRE royal blue.

 

[Bouncer]

Hi I have been reading this thread and I have a 180 tank that leaks so I have to take it down and replace with a 90 gallon. That being said, my wife has suggested that we re purpose this tank as my coffin. I said only if bury me nude. I would like to build an LED array, 36 inches by 12 inches with 36 cool white and royal blue LED's. These would be spaced 4 inches length wise and 2.5 inches across, staggered, with no lenses. I would like to do like Menthol did on his array. This tank would have mixed LSP, SSP and zoos and leathers. The tank is 18 inches deep, 18 inches wide and 4 foot long. I know that leaves a gap on all 4 sides. I would like to build this as cheaply as possible using Q5's....Suggestions Please ...Note my electronics experience is ancient and I haven't used it for years. Thank You For Your Time

Daytripper, you have your specs mixed up. 48x18x18 is nowhere near 90G. I'm sure it was a typo, but I think you should clarify this in order to get accurate advice... No Offence! I have a Nano 28G/48x18x24 90G myself & I will be going LED on both. When will you be converting over?

 

[daytriper]

I am buying this tank from a cousin of my mine and you are probably right. I just went with what I was told.I just did the math you are right.

 

[Reef_Matrix29]

Can I mount LED at 1" height? Do I need optics?

Are you referring to actual lighting or just moonlights or supplemental actinics?

 

[deral]

I'm thinking to make same LED like Satoki did but I got only 4,5" free space between water level and hood.

 

[der_wille_zur_macht]

Get a new hood. You're gonna have a huge headache trying to keep lighting clean and free of salt spray at that height.

 

[ReefEnabler]

Thanks for the info Kcress.....Can anyone comment on if people are still using the XRE Q5 or are people using the XPG's?

I am using both. Q5 Royal blues but using XP-Gs for the whites.

Honestly right now the XP-Gs are not a very big win, if at all, over the XR-E Q5s simply because there are limited optic choices. The ones ledsupply sells (carclo optics) say they support both MC-E and XP-G, but I can tell you they aren't very efficient with XP-G, betwen 70-80%. When I first fired them up I wasn't really impressed, didn't seem any brighter than XR-Es and that's almost certainly due to th optics being less efficient. The optic isn't really sized for the XP-G die and lots of light spills out.

Ledil recently came out with a bunch of new XP-G optics that I'd like to try, but most of them don't look easily usable on a star base, you would have to cut notches for your wires.

http://www.ledil.fi/index.php?page=xp-g

However I'm curious about this little guy wth a 67deg FWHM pattern and 92% efficiency:

 

[firebirdude]

updates?

 

[ddwbeagles]

Chris,

There was a group buy on nano-reef.com (now closed). Alot of people bought the XP-Gs (only cool whites were available). I already have some XR-E CWs (12) but I ordered the XP-Gs (40). The XP-Gs seem to have a more limited selection of optics (40 degree and 30). My next LED build will have a mix of the XR-Es and XP-Gs

Bob

Yep was in on the "Deep" group buy and ended up with the same combination and in the same "bind" concerning wider optics for the XP-Gs. That will teach me to do my research first. Got in on the GB right at the tail end and didn't have time to really know exactly what I needed. Live and learn.

 

[ddwbeagles]

Just a couple of tid bits to add. Still waiting on my MW 48Ds from a GB purchase, but have started doing what I can with my LED build to prepare for their arrival. I have a 8.5" x 21" heatsink. I started off sanding the contact surface with 1000 grit automative grade wet/dry sandpaper, then graduated up to 1500 grit, again following up with many polishing of Turtlewax "Polishing Compound". Needless to say, I was making progress, but it was extremely time consuming.

Out of curiosity, I applied some "Mother's Mag & Wheel" polish. BAM - mirror shine in one application. Not that I was going for reflection as LEDs are directional, but I did want a smooth flat surface to insure there will be optimal contact between the PCB Star and heatsink. Anyway, all this is probably overkill, but if you're going to buff out your heatsink, this was a real time saver over the polishing compound.

Next a quick question. I haven't drilled my HS yet and this seems to be the most common method of mounting. Not sure of the name of the product, but most LED vendors are also selling a type of LED adhesive tape (for a lack of a better description). Curious why so few use it as it certainly has to be a lot easier and quicker. What are the drawbacks from it? (if any)