I wish some one would come up with a better formula than the watt per gallon

Discussion in 'Reef Lighting' started by guidedbyechoes, May 28, 2011.

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  1. m2434

    m2434 Giant Squid

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    By the way, coverage area can be calculated as ((lens angle / 2) TAN * distance) * 2

    You probably want to estimate this at midtank or higher. So, if your tank is 18" and your putting them 6" off the surface of the water, distance would be something like (0.5 * 18 ) + 6 = 15" I would probably also replace the *2 with *1.5 or so as light will not be as good at the edge of the coverage area.

    So, in this case, for 60deg optics, figuring a given led will cover about a 13" circle would be a reasonable estimate.

    ((60/2)TAN * 15) * 1.5 = 13
     
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  3. gcarroll

    gcarroll Zoanthid

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    Better not use that formula with the Orphek optics info
     
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  4. guidedbyechoes

    guidedbyechoes Spaghetti Worm

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    My biggest reason is the cree leds are 5 dollars each for the cheapest ones I could find. My friend also said they all had heat sink attached to them. Any one know of the same leds without the heat sink? Seems overkill with two heat sinks. If I did this build, I would include a fan. I don't like not having the option to use one.
     
  5. Dingo

    Dingo Giant Squid

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    I don't think that Cree has Heatshinks that are attached to the diodes... Do you have a website?

    In the past I have used rapidled.com for my Cree needs. On the other hand, a repuitable halide bulb wouldn't pose any of these problems and would give higher quality of light...
     
  6. guidedbyechoes

    guidedbyechoes Spaghetti Worm

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    Nevermind my friend must have been mistaken. It is actually pc board. The cost of the cree led is my biggest detourant from going led.

    And the cost of running the halides. As well as replacing them every year.
     
  7. sostoudt

    sostoudt Giant Squid

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    If you have a 55 don't get halides, there isn't a appropriate wattage to be using. they cover around a 2 square foot area. So you would need 2 of them, that means 2 150's. thats a extra 100 watts and more heat.

    I would get t5 if I was you. with either ATI or giesman bulbs.
     
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  9. sostoudt

    sostoudt Giant Squid

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    Also I would like to say replacing t5 isn't that bad, considering its only once a year.

    If I may recommend aquacave.com for shoppign, they come with bulbs you can choose on some of them(not stock).
     
  10. guidedbyechoes

    guidedbyechoes Spaghetti Worm

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    I also think this might be the best route. I do also want to get some moon lights so maybe I can do a small project. That way if I ever see the need to switch over I will have enough experience to be able to do it. I'm gonna be using this 55 for a while I live with two others in an apartment and my target is a 180. So its gonna be a looooong while mostly before I get another upgrade.

    Thank you to ever one that contributed. I have a much better understanding of the different types of light and how the water affects them. I'm quite glad I joined here. I was previously at another forum and those helpful it took weeks to get questions answered. It also uk based so I had to do a lot of conversions to follow along. Thanks again.
     
  11. guidedbyechoes

    guidedbyechoes Spaghetti Worm

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    Yeah if I only get 2, that would add up with 4-6 like some run.
     
  12. m2434

    m2434 Giant Squid

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    I think 4 would be the minimum on a 55g. Make sure to get a fixture with individual reflectors. It's all about focusing the light down, not out. The replacement on 4 isn't bad, you can get them online for about $20-$25 each, so figure $80-$100 per year. Just order them when your ordering other supplies and get the free shipping.

    MHs are nice, but as mentioned, they aren't really well suited to the narrow rectangular shape of a 55, so they are somewhat inefficient in that regard. 2x175s would the most versatile for a 55g, but there aren't many 175 options out there anymore. 2x150s with good reflectors would work though. A Lumen max or Lumen bright reflectors are probably about the best out there, but are expensive. They do let you raise them up higher too though, so there is less heat issues, especially with something like a lumenbright "mini" reflector. It is made to be raised 16-18" or so. I think leds or T-5s will be the most economical if your on a budget.