Looking for heatsinks

[StirCrazy]

Originally Posted by justincgdick

One thing many people fail to take into consideration is once you add in everything, aka you need more LEDs for the same amount of light, you can't run Steve's leds at the same currents (aka 1000mA max for XP-G, 3000mA for XM-L), the forward voltages are higher = more power use... long term a Cree setup will very likely save you money.

For example a Cool white XP-G puts out around 270lm at 2.4 watts while a 3 watt Pure White 7,000K LED - 2 Chip EpiStar puts out 220lm at 2.4 watts.

So if you are running 50 R5 Crees ($4.95 on ledgroupbuy.com) at 700mA they put out about 260lm each using 2.27watts. You are putting out 13 000lm using 113.5 watts.

To get the same amount of lumens from the EpiStar quoted above you would need 59 (at $3.49each) leds running at 700mA using 141.8 watts. That a difference of 9 more leds and 28 watts of power. I typical reef setup of a large tank could easily use 30-60 more watts to run and 10-20 extra LEDs.

50 XPG is $247.50
59 EpiStar is $205.00

Once you factor in the price of the extra LEDs, possibly more drivers due to higher forward voltages (the forward voltage listed isn't precise, so I can be sure), possibly more heatsinking, wiring, adhesive/grease/screws/tapping and energy use of many years it isn't necessarily more expensive to use Cree.

Just food for thought. Steve's LEDs is highly recommended and I've only heard good things. I'm not trying to bash the company in any way. I'm just saying, consider everything.

yup this is true but.. you may not need extra LEDs at all, the coverage is going to be the same if you have the same degree of lense so coverage wise the amount of leds will remain the same. power wise.. you may not need all the power available to a cree. there are countless people who have there crees running at 700mA then they are only using about 60% of that.

so for a smaller tank under say 18" of depth, if steve's LEDs will give you the PAR you want on the bottom of the tank, why spend extra?

the only issue I am having now is for white I want nutral white not cool white, and I want to get ahold of a few TV LEDs to see the color mix befor I buy a lot. this presents a problem as Steve only has 7000K and 10000K whites and royal blue not the 5000K I want for white or the TV I want to test out instead of the RBs

Steve

[justincgdick]

Originally Posted by StirCrazy

yup this is true but.. you may not need extra LEDs at all, the coverage is going to be the same if you have the same degree of lense so coverage wise the amount of leds will remain the same. power wise.. you may not need all the power available to a cree. there are countless people who have there crees running at 700mA then they are only using about 60% of that.

so for a smaller tank under say 18" of depth, if steve's LEDs will give you the PAR you want on the bottom of the tank, why spend extra?

the only issue I am having now is for white I want nutral white not cool white, and I want to get ahold of a few TV LEDs to see the color mix befor I buy a lot. this presents a problem as Steve only has 7000K and 10000K whites and royal blue not the 5000K I want for white or the TV I want to test out instead of the RBs

Steve

This is true.

When most are dialing their LEDs back so much, up to 40% in some cases, I can't understand why the recommended number of LEDs isn't adjusted. If you need half the LEDs, fire some 60 or 40 degree optics on half the number of LEDs and raise the fixture a bit. Get your coverage, save money, keep the intensity and the best advantage, the change in par at different levels of the tank won't be as drastically different due to the inverse square relationship of the intensity to distance for the LED.