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reefgeezer
10/26/2011, 11:17 AM
I have an old Coralife fixture on my 75 SPS system that was originally 2X 150W HQI and 2X 96W PC. I still use the HQIs but have modded the PCs to 6X 28w T5HO "on the cheap" using Coralife's electronic ballast that was driving the old PCs and end caps taken from a Lowes T5 fixture. This worked OK, definitely brighter and the bulbs lasted longer than the PC's. But now that the bulbs need replacement, I'd like to do a permanent mod with a proper ballast, reflectors, and waterproof end caps.

I'm planning on using four 54w T5HO bulbs instead of the six 28w bulbs. My initial questions are these: What ballast should I use? Is over-driving the bulbs a good idea? Where is the best place to buy the retrofit components?

Any other thoughts or comments would be greatly appreciated. Thanks in advance for your advice.

reefgeezer
10/26/2011, 07:58 PM
Bump

TheFishMan65
10/27/2011, 09:12 AM
Have you considered LEDs? You won't have to replace the bulbs later. 24 LEDs would probably replace the four 54w T5s.

reefgeezer
10/27/2011, 09:49 AM
Have you considered LEDs? You won't have to replace the bulbs later. 24 LEDs would probably replace the four 54w T5s.

Thanks for the reply. I saw your post in the other forum also. Sorry. Patience has never been one of my virtues.

I would love to use LED's but I just don't understand how to build them. Drivers - Buck Pucks - Back Voltage, I don't have a clue! I can solder and understand simple wiring diagrams, but for some reason, I just can't get my head around LED DIY. I'd really, really like to build two strips into the Coralife fixture. I think I'll spend about $350 modding my fixture (including bulbs) to the 4X 54w T5's. Could a 24 LED DIY be done and the extra costs recovered in a couple of years?

TheFishMan65
10/27/2011, 10:49 AM
24 LEDs at $5 = $120
2 ELN (maybe one) at $35 = $70
Heat sink $$
That is the main expense. I am building one for someone with 48 LEDs and it is a little over $400 for parts, but I do have a cheap source for heat sink material. IMHO you can do it for less that $350.

Let me see if I can find the thread that had a real good wiring diagram.

reefgeezer
10/27/2011, 11:40 AM
I can get scrap aluminum U-tube from work to use as a heat sink. I've also got a couple of scrap computers that I can tear down for the fans. I've read that Cree XR-E's are the lamps to use. It looks like I could buy 24 of them mounted on Star Boards with optics for just a little more than I'd spend on new T5 bulbs for one year. It also appears that the power supply wouldn't cost too much. That makes the project seem pretty do-able.

I guess my questions change now... What optics and power supply(s) would be required? What color mix should I use considering I'll still use the 10,000K HQI bulbs also? Should I make color groups individually dimmable so the CRI can be adjusted and what hardware is required for that?

Please pardon my exuberance, but this seems like the answer I've been looking for. :bounce2: Once again, thanks in advance for your help.

TheFishMan65
10/27/2011, 11:40 AM
Hmm, I wonder where I posted this (http://www.reefcentral.com/forums/showthread.php?p=18779114#post18779114)?

That is a good picture of how to wire it up. I thought I posted, but either I forgot to click reply or I did it somewhere else.

Let me know what kind of questions you have?

TheFishMan65
10/27/2011, 11:44 AM
I would use XP-E for royal blues and XP-G if you add white.

Check out the ELNs for power supply. If you want to learn about parallel builds you could get away with one other wise two.

Optics depend on height above the tank?

I would probably just do the royal blue. You can turn them down if it is too blue. 300 watts of MH should be enough on its own for a 75. You are just trying to add pop so why waste money on other LEDs. Now if you want to replace the MH, we can keep talking.

reefgeezer
10/27/2011, 12:58 PM
Thanks so much. I think I'll try my hand at the 24 LED build before I try to replace my metal halides.

TheFishMan65
10/27/2011, 01:43 PM
No problem, let me know what I can do to help.

reefgeezer
10/27/2011, 02:18 PM
The fixture is only about 6" above the water so I may not need optics. I think I'll just use Royal Blue in this set-up. XP-E's are 5.89 at LEDSupply. Do you know a cheaper source?

TheFishMan65
10/27/2011, 02:23 PM
RapidLED $3.40 Here (http://www.rapidled.com/servlet/the-124/CREE-XP-dsh-E-Royal-Blue/Detail)

You can probably find a little cheaper, but I have ordered lots from RL and know what I am getting. Plus great service.

der_wille_zur_macht
10/27/2011, 02:25 PM
No optics at that height.

There are lots of sources cheaper than LEDsupply, search around through build threads and you'll see some ideas. A high-bin XP-E on a star MCPCB should be more like $3.50 - $4.00.

reefgeezer
10/28/2011, 08:23 AM
Crap! I just checked the date on my metal halide bulbs. They need replacement also. How many more LED's and Drivers would it take to replace 2X 150W HQI fixtures? What color mix would you recommend? I like the 10K halide with super atinic VHO look.

Thanks again.

der_wille_zur_macht
10/28/2011, 08:33 AM
I have an old Coralife fixture on my 75 SPS system that was originally 2X 150W HQI and 2X 96W PC. I still use the HQIs but have modded the PCs to 6X 28w T5HO "on the cheap" using Coralife's electronic ballast that was driving the old PCs and end caps taken from a Lowes T5 fixture.

So the total fixture is:

-two 150w DE MH lamps
-six 28w T5HO

Are you hoping to replace this exactly in terms of color and intensity, or are you looking to alter either variable at all? What brand and model of lamps are in there for both the MH and T5?

In very rough terms, for a 75g SPS tank with very high intensity and using typical LED practices, you'd probably end up at around 48 LEDs total. There's a very big personal-choice component in all this, but you might end up with something like:

-One ELN 60-48 at 1.3A running 6 cool white XP-G and 6 neutral white XP-G all in series
-One ELN 60-48 at 1000mA running 6 white XP-G (choose cool white or neutral depending on your color preference for a warmer or cooler tank) and 6 XP-E royal blue all in series
-Two ELN 60-48 each running at 700mA with 12 XP-E royal blue, or one ELN with two strings of 12 in parallel, if you are OK with a parallel build

I'd build four aluminum u-channels with 12 LEDs on each, spreading the various colors evenly across the tank. Put them behind an acrylic splash shield and you're done.

(Bonus points for building a Typhon controller to dim the four drivers!)

TheFishMan65
10/28/2011, 09:20 AM
+1, but you also might want to consider 4 regular blue as replacement for 4 of the RB. I have read good things on doing this - sorry nothing personal yet.

reefgeezer
10/28/2011, 10:21 AM
Thanks Guys. I have been using 2 150W Aqualine Busche (sp?) 10K DE Metal halide bulbs and 6 28W Guiessman 4 Actinic Plus and 2 Pure Actinic. If I build a new fixture I really would to build one to support the SPS corals that has a slightly warmer look than I have when my current bulbs are new, but still has enough blue to make the corals and clams pop.

I think I can afford to build the 48 LED fixture and don't mind parallel wiring. Heck, I don't think I can afford not to build it. Will 48 LEDs really give me the same PAR as my old set-up? The Typhoon controller sounds interesting also.

reefgeezer
10/28/2011, 10:47 AM
Here's one of those questions people who don't have a clue need to ask... How does the amperage that is used to run particular strings change? I notice that some are run @ 1.3 amps and some are run @ 1 amp (1000 ma), while others are run at 700ma. Is there a switch or resistance change required to do this or do the LEDs particular to the string make the difference? :confused:

TheFishMan65
10/28/2011, 11:08 AM
That is handled by the driver. The ELN has a 0-10 volt signal that allow it to adjust the current. This can be done easily with a 10 volt power supply and a 10k potentiometer.

der_wille_zur_macht
10/28/2011, 11:10 AM
Thanks Guys. I have been using 2 150W Aqualine Busche (sp?) 10K DE Metal halide bulbs and 6 28W Guiessman 4 Actinic Plus and 2 Pure Actinic. If I build a new fixture I really would to build one to support the SPS corals that has a slightly warmer look than I have when my current bulbs are new, but still has enough blue to make the corals and clams pop.

Given this, I might suggest using all neutral white and no cool whites, or at least a majority neutral. You can always buy a few extra of each color and play with the ratios to tweak it.


I think I can afford to build the 48 LED fixture and don't mind parallel wiring. Heck, I don't think I can afford not to build it. Will 48 LEDs really give me the same PAR as my old set-up? The Typhoon controller sounds interesting also.

Parallel wiring is only really practical on the string(s) of XP-E. The XP-G are typically run at currents higher than the ELN can support in parallel. Going parallel saves you the cost of one driver and potentially bumps your efficiency up a few percent but it requires some extra effort to do correctly - search the forum, there have been a few good threads.

The Typhon (one "o") is described in this thread:

http://reefcentral.com/forums/showthread.php?t=1847680

Here's one of those questions people who don't have a clue need to ask... How does the amperage that is used to run particular strings change? I notice that some are run @ 1.3 amps and some are run @ 1 amp (1000 ma), while others are run at 700ma. Is there a switch or resistance change required to do this or do the LEDs particular to the string make the difference? :confused:

LEDs can be run at a range of currents, the power level is not set firmly as with other forms of lighting we are used to. All of these LEDs are rated with a maximum current. The manufacturer typically specifies performance at several points below that current, which gives you an idea of how their performance and efficiency changes at different currents. It's basically a tradeoff - higher currents means higher intensity, but at a lower efficiency - you're getting more light, but burning more power per unit of light. As such, many people choose to run the LEDs at a "sweet spot" of somewhere around 70% of the maximum, because that provides a good balance between output and efficiency. As long as you don't go over the LEDs' maximum currents, it is basically up to you, but if you're talking about a "typical" build on here most people are within a few dozen percent of the max.

How I arrived at the numbers above:

The Cree XP-G has a maximum of 1.5A. The ELN 60-48 has a nominal maximum current of 1.3A and that is happily under the maximum for the XP-G while still getting good efficiency and brightness.

The Cree XP-E has a maximum current of 1A. Hence on the string where you're mixing XP-G and XP-E together, you need to stay under 1A. Choosing 1A gives decent performance and efficiency from both models.

The driver(s) running ONLY XP-E I suggested 700mA for simply because that's a little better efficiency for the XP-E.

Regarding setting the current - it depends on the driver. The ELN series have two internal trimpots that change the behavior of the driver. One of them adjusts the target drive current - it basically lets you dial in an exact drive current within the specified range of the driver.

der_wille_zur_macht
10/28/2011, 11:25 AM
That is handled by the driver. The ELN has a 0-10 volt signal that allow it to adjust the current. This can be done easily with a 10 volt power supply and a 10k potentiometer.

Together we gave the complete picture. :D

To be clear, the ELN has two features for adjusting current, designed with different use cases in mind.

First, there's the internal trimpot I mentioned. This is basically meant to be set when you build the fixture to determine your nominal operating current.

Secondly, there's the connection for an external 10v dimming signal. This is meant to be used "in production" to vary the current to levels below the nominal current set by adjusting the internal trimpot, i.e. to allow dimming each day for sunset and sunrise on a reef tank.

TheFishMan65
10/28/2011, 12:34 PM
Here (http://www.reefcentral.com/forums/showthread.php?p=18779114#post18779114)is a real good wiring picture for the ELN.

reefgeezer
10/28/2011, 12:35 PM
Thanks guys. I'm starting to understand. Thanks for the patient responses.

TheFishMan65
10/28/2011, 12:45 PM
If you decide to go parallel let me know. There is another good picture here somewhere that I will try and track down.