Exploring DIY LED fixture to replace 3x MH 250w (10kK) + dawn/dusk + moonlights

[Ashlar]

I'm in the investigation stage of replacing my metal halides with LEDs.

My tank is 60" wide x 18" deep x 30" tall. That's 108 sq in of surface. I have a big honking center brace 15" wide that doesn't pose a problem for MH. Above the tank I only have 18" of distance to the ceiling.

I have corals within 5" of the surface as well as on the sand bed.

Right now I'm running two PFO pendants on the ends and a hamilton pendant in the center (the hamilton has a nice reflector that spreads evenly.) No canopy. I also have an old CF fixture that I use for dawn / dusk, and a string of low powered LEDs that I use for moonlights.

So what does everyone think would be the best solution?

3 x fixtures? (Say a heat sink 8" x 16".) One 55-60" heat sink? How many LEDs would be recommended? I like the look of my XM 10k lights, but the wife liked the reeflux 12kKs I used to have (I ditched them because they didn't provide the same growth.) I used to spend a lot of time snorkeling in the shallow water of the keys, I just like 10-12kK as it's more natural.

My aquascaping is chaotic. I have lots of ledges and caves, but my MH does a good job of illuminating them evenly. I'd rather not have to plan my lighting/optics around my aquascaping in case it changes later (if I'm going to keep this thing for 10 years, it has to be general purpose).

I want to avoid creating shadows, especially different colored ones.

What I don't want is something like this with the LEDs too far apart..



or this with the LEDs too close together..



I understand that spreading them out decreases shaded areas and bringing them closer blends the colors better.. but what's the happy medium? Is there one? Or are you forced to choose between disco ball light separation to ensure coverage on one hand, or spotlighting to ensure mixing on the other? Or do you just stuff a truckload of LEDs in there, but only run them at 30-50%?

From looking at photos, I think I'm interested in the neutral white, with only a little royal blue for flourescence. Maybe some deep red and cyan to fill the gaps in the visible spectrum.

I've got time on this investigation, I couldn't pull the trigger until my tax return shows up anyway.

What is everyone's thought?

p.s. I'm not even getting into drivers, buck puck v meanwell v etc at this point, but I do want a lot of controllability.

p.p.s Here's a recent FTS- it's a bit brighter than the camera shows, but it's a good representation of my current color temperature.

[Wall_Tank]

Those pictures are horrible implementations of LED's.    But you have the concepts right.    Close enough together to blend, but far enough apart to not go broke buying LED's.

For the 10k look, go with a 50/50 mix of blue to white.    As for the heat sink.....I love the way my fixture is built.   60" long heat sink over a 72" long tank.......but that really makes the fixture heavy.    Is the center brace clear???     With your single center brace, I would go with 2 fixtures.   I would get the wider heat sink stock (10"), or make your own.   So probably a 10x24" fixture....... 

I ran 70 LED's over my 90, and 140 over my 180.   

[Ashlar]

The pictures and fixtures I've seen with 50/50 w/b are waaaaay too blue for me. Blech.

I like neutral white..



Maybe a little warm white (but not much..)

Is the center brace clear???     With your single center brace, I would go with 2 fixtures.   I would get the wider heat sink stock (10"), or make your own.   So probably a 10x24" fixture....... 

I ran 70 LED's over my 90, and 140 over my 180.   

The center brace is clear, but it's often got salt creep and / or mineral deposits. The MH has no problem punching through it, though.

[Wall_Tank]

Everyone's taste is different.    IMO 50/50 blue to white is still pretty warm.    You can go with a some warm whites, or just turn down your blues a little bit.   Pictures can be so deceiving with white balance, you may just have to buy 10 LED's and play with them before you get a fixture full of the wrong color mix.

[Ashlar]

Everyone's taste is different.    IMO 50/50 blue to white is still pretty warm.    You can go with a some warm whites, or just turn down your blues a little bit.   Pictures can be so deceiving with white balance, you may just have to buy 10 LED's and play with them before you get a fixture full of the wrong color mix.

Probably the best idea, yep. Why buy 50% blues and then turn them way down, when I could replace those with NW's.

Assuming I get a good feeling about this even working without disco ball or shadowing, I'll probably build a test rig with a handful of different colors and a few dimmable drivers.

[Wall_Tank]

Probably the best idea, yep. Why buy 50% blues and then turn them way down, when I could replace those with NW's.

Because I think your mind will change when you see what a little blue LED does for your tank

[Ashlar]

I've had 12k, and I've seen 20k. I despise it.

I used to spend a lot of time with my wet behind in the air in the florida keys. This blue crap just doesn't appeal to me.

[Wall_Tank]

I've had 12k, and I've seen 20k. I despise it.

I used to spend a lot of time with my wet behind in the air in the florida keys. This blue crap just doesn't appeal to me.

We just have to turn you to the Dark Side 

Seriously, just get some and test it out.   you can do 8 LED's on an ELN30-27D.   You won't be able to control each LED for testing, but you can play with the mix.

[Ashlar]

*nod* I'll prolly get 2-3 drivers so that I can mix and match. Maybe pick up some 30-24Ds, so that I can play with the mixing and matching. I've got a 30g hex tank that I can use as a test bed.

[Neogenesis]

I honestly think you would like 50-50 using XP-G's for white, and XP-E's for blue.  If I could take a decent photo, the center of my tank is a great example.  Mix the whites between cool white and warm white to help bring out the red spectrum, you would be right on par.  If you mix in red's you will definitely get a disco ball effect, I hated it when I tried it. I haven't tested any violet yet, but plan to mix a few in after Christmas.  As for optics, a little research would be needed, but in my 24" deep tank, I'm moving away from 65 degree optics and am going to try 80's.  It should lessen the par on the sandbed a bit, and promote better color mixing.

I'll see if I can get some better pics......I've got 50/50 XRE-Q5's running and 50/50 XPG, XP-E fixtures.

Scott

[Ashlar]

Here's my tank right now..

http://www.rowelab.com/fish/camera/index.php

10k.. 10k.. 10k..

From photos that I've seen, I'd be happy with all NW, plus a smattering of RB.

[HUNGER]

thats cool

[Neogenesis]

agreed.....that's cool.  Not sure what your doing buy I see your hand in the tank!!!

[Ashlar]

agreed.....that's cool.  Not sure what your doing buy I see your hand in the tank!!!

Lol, woops- I was scraping some nasty palythoa away. I've tried injecting them with various and sundry concoctions, I've tried zapping them with electricity.. nothing works- but a sharp blade and patience does.

[DarinSchmidt]

If you are using XPG's, They can go up to 1.5A, but that will make them pretty warm, but, you will be able to drown out some of the blue coloring since the RB/B's are XRE with a max of 1A, plus the XPG's put out a considerable amount more lumens so you shouldnt need to bring the amps up to 1.5 to get the coloring you are looking for.

I used the RB's because i wasnt a big fan of the ultra blue aquariums i saw online, but i'm a fan of the CW/WW mixture, I plan to replace some of my CW's with some WW's soon when i place an LED order as soon as i get my price list i requested.

[Ashlar]

That sounds great, Darin.

On another note, has anyone seen this?

http://makersled.com/

This looks really interesting. If it's fairly cheap when it comes out, I might consider using some of it.

[Neogenesis]

Very interesting......wish it were available now.....I would try a kit out. 

[Ashlar]

So any more input? Any recommendations on:
-LED spacing for a 30" tall tank
-LED height above the tank
-LED optics to punch to the bottom of the tank but not have color separation at the top
-LED mix to duplicate an XM 10kK

I'm working up some different options in sketchup, curious to see what folks think.

[Wall_Tank]

Here is my build, starting with my fixture that I designed in Solidworks.
http://www.ohioreef.com/index.php?topic=10931.105

I have LED's spaced from 1.5x1.5 to 2x2.   Not sure I would go much more that 2x2

I would recommend 80degree optics in most places, with some 60 deg optics carefully placed to reach the sandbed.

My fixture is mounted about 12-13" over the water.....15" would probably be better.

[Ashlar]

So as mention upthread, I'll probably start with a block of aluminum and try some different combinations..

I sketched up a primitive version of what that makersled heat sink might look like so that I could get a feel for some different combinations and spacing..

My starting point would be a couple of neutral whites, warm white, royal blue, blue, cyan, and deep red.



If that color combination works, maybe something like this.. (18" x 7", 1.25" diagonal spacing)


And yeah, I'm tempted to go with one 55-60" block of aluminum, rather than three fixtures, too. (Especially if that makersled heat sink is delayed or really expensive.)

[Wall_Tank]

I still think its not enough blue, but the pattern should be fine.   Probably a bit more dense than needed.

[Ashlar]

I'd rather have more light and not need it (dim it down) than have to go back later and add more / move a lot of lights.

My test rig of 10 should give me a good feel for color, assuming I splurge and pick up 5 or 6 dimmable drivers. I figure I'll pick up a handful of optics as well, say 3 each 40, 60, 80 degree.

[Wall_Tank]

My test rig of 10 should give me a good feel for color, assuming I splurge and pick up 5 or 6 dimmable drivers. I figure I'll pick up a handful of optics as well, say 3 each 40, 60, 80 degree.

Sounds like a plan.....plan out your drivers for use later.   Do you have use for small drivers later on?

[Ashlar]

Sounds like a plan.....plan out your drivers for use later.   Do you have use for small drivers later on?

Assuming the red / cyan / warm white add value, yes. That'd be 8 WW, 3 RB, 4 CY, and 4 DR in the larger version, so those could be reused.

I've also got a 30g hex coral QT in my office, if I wanted to keep the test rig as an actual light.

[referinohio]

Here is an article I found while researching for my led build I'm getting ready to do.
Just got the leds from Rapid led yesterday. My goodness they are bright!  Hopefully heatsinks tomorrow. Just got an email that they shipped today. 
Hope this helps.

http://reefledlights.com/ledmytank/