Led ?

[reefs4life]

For those of you who have knowledge on LEDs, I have a couple of questions that I'd like to ask. If I were to replace a 250w MH with a 100w LED that produces 7000-8000lm at a color temp of 6500-7000K, would I be giving my corals an equal or greater amount of light as my 250w? My plan is to just put a few powerful LEDs in the place of where a MH would fit in a standard coralife aquapro light fixture. I also saw 20000K 10w LEDs that if I planned on going with those I'd probably put 8-12 of them per 250w MH. Also, is a 48V led driver the highest one out there? I've been looking at drivers and the voltage doesn't go up that high to be able to use few drivers with many leds, for example the 10w leds use 10-12v which means I can only run 4 in series with a driver from what I've understood about wiring LEDs. I appreaciate the input. Thanks, Fortunato

 

[ming]

If you wanted to know how many lumens the LED's will give off, you'd need to look at the datasheet of the specific LED's you have in question. Every LED will give different lumen per watt based on efficiency. You'd probably be more interested in PAR comparison, but that's usually not available in the datasheet. As for the drivers, your calculations are correct. Although with the Meanwell ELN 48-60 drivers, they're usually around 1.5A so you could run 2 parallel strings at 750mA, but you'd need to add a fuse to the strings in case 1 LED's pops so the other string doesn't get the full 1.5A and burn out. At 750mA, they're usually around 80-90% brightness if 1A is maximum brightness.

 

[Deep Dive Coral]

when choosing led arrays you must consider the depth of tank you have as well. here is where optics come in. the number of leds that you use do not essentially give you a higher par rating. all the number of leds used is for coverage. the more leds to greater the coverage. the less leds the less coverage. optics is waht increase the par value of each led. the lower the optic degree the tighter the light beam. if you dont have enough leds then you get that spot light effect. which btw looks pritty cool to show case a specific coral.. its used alot in japan. but back on track. each led already has an optic built into the led themselves. depending on the brand you use and what led and bin etc.

if you need any advice there are a bunch of us that know a little something about these leds......

 

[reefs4life]

Thanks for the info guys...

Ming, the 100W LED that I'm talking about does produce 7000-8000lm, that's what it says on the datasheet of that LED. My question is though, is that 7000-8000lm comparable to the lm produced by a 250w MH? And as I mentioned earlier, I saw these 20000k and 15000k 10W LEDs, which if I chose those I would use 8-12 of them, each one producing 800-1000lm, giving me a total of 6400-12000lm, which I'm wonding if it is comparable to lumens of a 250W MH.

 

[Deep Dive Coral]

Lumens is only the brightness of the light. Par is what you need to compair that its the usable light for the corals.

 

[reefs4life]

so I just got one of these 20K 10w LEDs and man is it bright and it has a really nice blue tint to it. Wouldn't even need blue LEDs to mix in with it, I could just get a few for dawn/dusk affect and night light. You guys think it would be worth it to build a fixture for my 210 out of these LEDS. If so how many do you guys think I would need, I would probably do 1/2 20K and they also have 10K so I'll mix them up like that possibly

 

[reefs4life]

Anyone have an opinion?

 

[stage3-S4]

As far as comparing LEDs to MH its not a very easy thing to do. If you were to look at the lumen output of a typical MH lamp, you would see that the lumen output is way higher then a typical array of LEDs. This is mainly due to the fact that MH radiate light in a 360 degree radius hence the use of reflectors. I would suggest buying a borrowing a PAR meter and doing some testing to see the typical output for one of these LEDs at the desired height and compare it to that of the 250w HQI. This will give you a general idea as to how many you would need. Looking at data sheets is not really going to help you that much. Its just to be used for general approximations. Let me know if you have any other questions, I would have no problems helping you out.


Sent from my iPhone using Reefs

 

[Deep Dive Coral]

I don't know much about those leds. From what I read is that the 10k leds are on the yellowish side. The reason why people mix the cool white and royal blue leds are so they can adjust the color temp to their liking. I feel you will have less controll in the light. Also you said it was 10w at 800-1k lumens. In my opinion that is sub par to what is out there. My cree leds are 107 lumens per watt. 3w per. So with more control and probably better light mix I am going to get the same exact par readings as you. This is the reason why I think the 10w leds haven't really took off yet.

 

[Aqua Pro Builder]

If you have it set up with a heat sink and readily movable, bring it to my table in the swap. I bring a PAR meter to test for you.

When comparing MH vs LED, there are couple aspects MOST people (including couple LED speakers in the reef community) forgot about. You have to take the color temperature, and the angle where you are taking the measurement into consideration, especially in terms of height of the tank. Note that the par taken at the bottom of a tank's edge is usually higher than the par taken say 6 inch from the top of the tank at the same edge.

If you want to test it even more comprehensively, draw a grid the size of you tank and we take a lot more data in relation to height and angle in your particular case(tank.)

 

[reefs4life]

If you have it set up with a heat sink and readily movable, bring it to my table in the swap. I bring a PAR meter to test for you.

When comparing MH vs LED, there are couple aspects MOST people (including couple LED speakers in the reef community) forgot about. You have to take the color temperature, and the angle where you are taking the measurement into consideration, especially in terms of height of the tank. Note that the par taken at the bottom of a tank's edge is usually higher than the par taken say 6 inch from the top of the tank at the same edge.

If you want to test it even more comprehensively, draw a grid the size of you tank and we take a lot more data in relation to height and angle in your particular case(tank.)

Ok cool, thanks Wingo. I don't have it set up with a heatsink but I think it would be ok for a few mins just for testing no? Also, the 12v power supply I tried it with is hooked up to my 20G fan so would you happen to have one with you or should I see if I can bring my own? It's kind of bulky lol