Too much light?

Discussion in 'Equipment' started by itsacrispy, Sep 25, 2017.

  1. itsacrispy

    itsacrispy Supporting Member

    Hi all,

    After several years off I finally started up a small 20 gallon long mixed reef tank. The tank has cycled and I just added a pulsing Xenia. I noticed that the Xenia is open an pulsing in the early morning, right when the lights turn out. However, as the day goes on, the Xenia closes up as the lights get brighter.

    I have a Kessil A360W Tuna about 8" above the tank. The lights are on for 15 hours but reach max brightness between 12pm and 4pm. Could my lights be too bright for the tank? I don't know what else it could be, ammonia and nitrites are 0, nitrates are <5ppm, pH is 8.2, dKH is 7.5, and temp is 77F.

    Would appreciate any thoughts, thank you!!!
  2. Gablami

    Gablami Supporting Member

    Hi there. Welcome to reefing! Just about all corals have an ebb and flow to them. In general, as long as the corals are fully extended and look happy for a portion of the day, I would say they are doing fine. With time they may further adapt to the environment and be open longer.

    That said, an A360 is a lot of light for a 20g tank. If you're running it max you might be blasting the whole tank. The Xenia may be fine, but there are lots of other corals that may not do as well. If you're curious and want to quantify the lighting, you can use a PAR meter. BAR members can borrow the club meter, FYI.

    Sent from my iPhone using Tapatalk
  3. itsacrispy

    itsacrispy Supporting Member

    Thank you! I should have noted that I am running the brightness at 85% at max with color at 100% at max. I'll check to see if I can borrow the PAR meter, been a while since I was active :p

    EDIT: The Xenia is at the bottom of the tank on the far right corner, I will try to post a picture of it later but I'm not sure if the light is affecting it.
  4. Chromis

    Chromis Supporting Member

    The club PAR meter doesn't work on Kessils (don't know if I should generalize to all LEDs). I have never run a 350W above about 50% so you are probably burning your corals. I would start at 30% and work your way up.
  5. coral4me

    coral4me Supporting Member

    I never turned my A360we over 65% power intensity on a 24" tall tank. ( Additionally, I probably would not go to 100% in white color. I'd max the color around 80%-85% or less )
  6. watch the coral, if it shrivels up and melts away, too much light.. if it is stretching not enough light...i would err on not enough light..corals dont die as fast that way
  7. itsacrispy

    itsacrispy Supporting Member

    Thanks all, I've turned down the intensity to 30% max for 4 hours during the day, total of 15 hours. I will turn down the color to 75% as well as see how that goes. I really appreciate your advice!
  8. F6553066

    F6553066 Guest

    Have 2 350's and 1 360w. the above advice to start at 30% is good. You can then increase the intensity by 5% very 2 weeks, which let the corals accumulate to the light. Once you reach 50% any further increases will depend on the type of coral you want to keep. These lights are pretty powerful and too much light is much worse than too little. I would think at 50% you can grow most corals. Lastly, the color setting will have little or no difference won the corals growth. Kessil has programed the lights so the spectrum is the same no matter what color you chose. So pick the color you like, and then just change the intensity up,or down.

    Dick Flanagan
  9. Actually this isn't necessarily true. I have zoa colonies that are stretched right next to colonies that don't. Some species of Zoa's simply act differently from others. Bottom line is if a colony has heads that fully open it's fine.

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