Kelvin rating

Discussion in 'General Discussions and Advice' started by Zenith, 7 Sep 2009.

  1. Zenith

    Zenith

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    Hi Guys

    How can you measure kelvin in your tank, i take it if lets say you have 2 10000k lamps and 2 20000k lamps your kelvin rating should then be aroun 15000k or am i wrong. Also do you kelvin rating drop as it goes deeper into the tank and will th kelvin rating of a lamp degrade with age.

    Thanks people
     
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  3. viper357

    viper357 Admin MASA Contributor

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    I don't think you can, unless you spend a few grand on an incredibly expensive meter.
    ummmmm, I suppose so :p
    I think it does drop as I recall the red light is filtered out as you go deeper.??? I would say the Kelvin rating, as well as the PAR, PUR etc all degrade or decrease in intesity as the bulb ages. A white light will tend to start giving off a more yellow light as it gets older.

    It is strongly advisable to replace all of your lights/tubes at least once a year to prevent all of the above.
     
  4. martinhal

    martinhal

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    Interesting so tagging along.... my 2c worth

    I dont think one can average the K ratings so 20K and 10K lights dont equal 15k... I am guessing.

    I dont think that the K rating drops with depth it is just less intense.

    As the bul gets older the color does change so I guees it is a change in K rating but more importantly the intensity gets less.

    Lets see what the gurus have to add.
     
  5. Bob the (reef)builder

    Bob the (reef)builder

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    :):):)
     
  6. chikaboo

    chikaboo

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    I think this is a mistake I made when I first started : I thought taking a few 6400K bulbs added up will give me a nice big "K" rating but I was wrong - I'm assuming this is the same for mixing K ratings across the spectrum? Light guru's what do your'll say?
     
  7. justinM

    justinM

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    wouldnt the higher K rated bulbs effectively cancel out the lower K rated bulbs?
     
  8. butcherman

    butcherman Moderator MASA Contributor

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    Isnt the kelvin rating the COLOR equivilent to heating up a block of carbon to that temprature? so combining diffrent colors just gives you a broader spectrum of light. atleast thats how i understand it. as for the deepth the lower you go the less intense the light becomes. Maybe someone can confirm what in thinking?
     
  9. Falcon

    Falcon

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    not really no.1 20000k ans one 10000k should average around 15000k but two 15000k globes will not give you the same broad spectrum as using two diff globes,since we dont know EXACTLY TO THE TEE which corals need which light(and even if we did then each corals needs are not the same) we rather be safe and give them a nice broad range of choice light to take in.and since it is said the higher ranges give colour and lower ranges give growth so using two tubes we max both.making sense ?

    spot on my friend.you pick up fast dont you:p
     
  10. Falcon

    Falcon

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    na he's not thinking along those lines he is not adding kelvin,he is averaging the colours which is a legit question and he understand more than you did:razz: thank goodness you had masa right?:thumbup::slayer:
     
  11. chikaboo

    chikaboo

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    True dude - felt like a real "genius" when I was buying but like a deflated balloon when did my research!
     
  12. Zenith

    Zenith Thread Starter

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    my plan is to put in a 6500k 250w low bay mh and run it for about 6-8hrs and run my current 10000k and 12000k t5`s before and after the mh and run my 20000k for the full 10 -12 hrs, does this sound right, i think 6500k is broud spectrum (normal daylight)
    I should then get 6500k exposure with 20000k for colour and 10/12000k with 20000k for the mornings and evenings.
     
  13. martinhal

    martinhal

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    Thats why I love this hobby !! Learn something every day...... nice one... at least it is better than the " wich is the best K rating debate "
     
  14. Falcon

    Falcon

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    that sounds fine,only thing i would include maybe some actinic with the 20000k so that the light wont look too yellow when the mh is on....
     
  15. Zenith

    Zenith Thread Starter

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    yeah i will be running the 20000k with both sets of lights
     
  16. justinM

    justinM

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    well explained falcon, my opinion though is to try keep it simple. instead of a heap of different lights (MH) find a happy medium
     
  17. Zenith

    Zenith Thread Starter

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    hi guys
    would a 4000k 250wmh work if i run it with 20000k fl
     
  18. Falcon

    Falcon

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    naa dont bother with anything less than 6500k and most people would use min 10000k for a display tank....the only people who use alot of 6500k are coral farmers looking for max growth.


    4000k will have too much light in the spectrum range that corals dont use resulting in alot of wastage.keep away from the 4000k for sure.;)
     
  19. Bob the (reef)builder

    Bob the (reef)builder

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    Also might encourage algae growth.
     
  20. Zenith

    Zenith Thread Starter

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    ok but the 4000k should be fine for now right , sort of a financial recession at present and the globe came with my fitting
     
  21. Bob the (reef)builder

    Bob the (reef)builder

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    Zenith, you can put anything above your tank. But the good advice is to not use a 4000k bulb, even 6500k looks pretty ugly.

    Using 4000k is giving a lot more unusable light and much less usable stuff. You will be wasting money(electricity) on useless ugly light to some extent. If the corals die, you will always wonder if its the light. And it will have cost you more than if you did it right the first time.;)
     
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