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  1. #1
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    LED lights scaring fish

    I recently moved everything from a 10 gallon to a 20 gallon long.

    The 10 gallon had 65W 50/50 PC lighting. For the 20 long, I kept the same light but built a hanging fixture and added 12 Cree LEDs (8 XP-E Royal Blue and 4 XP-G Cool White). The LEDs make the corals look amazing, couldn't ask for better colour.

    BUT

    I have the LEDs timed to come on about an hour after the PC lighting, and I noticed that while just the PC light is on, my fish (ocellaris clown, darwin clown, and royal gramma) happily swim all over the tank. As soon as the LEDs come on, the gramma goes and spends almost the entire day hiding in his cave (he NEVER hides when just the PC lights are on) and the clowns hang out at the back of the tank where it's not as bright.
    I tested my theory of the lights affecting this behaviour by turning them off and on and watching the fishes' behaviour. There's no doubt in my mind the LEDs are causing my gramma to hide and my clowns to hang out in one spot at the back.

    The LEDs are on a constant current driver so I can't dim them, I did try raising the lights higher above the tank (originally about 3"; now ~6" above) and the same thing happened.

    Right now I'm wondering if the brighter lights are freaking them out since they are also still settling into their new tank (it's been about a week) so I'm thinking of leaving the LEDs off for a bit until they are a bit more comfy. Or should I just leave the LEDs on in hopes the fish will get used to them?
    Any thoughts?

    I should add that all my parameters are good (Ammonia: 0 Nitrite: 0 Nitrate: 0 pH: 8.2)

  2. #2
    liv
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    your not the first one i read about this exact same issue.
    some fish never seem to get used to it and usually jump off or die.. sadly.

    in your case.. i'd try to acclimate the fish first.. then in a few weeks slowly start them up with 2h a day a increase by 2h weekly.

    moving.. so temporarily out of SW :b8:
    planning next tank, possibly 60x30x20 on 2x plasma.
    updated: 2011/05/30

  3. #3
    liv
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    just speculations.. but it might be how narrow the led's shoot inside the tank.
    if it doesn't get any better.. I'd try and put a diffuser in front of the led's like a sand blasted piece of glass. this would smooth out the beams. ( and would dim them at the same time )

    moving.. so temporarily out of SW :b8:
    planning next tank, possibly 60x30x20 on 2x plasma.
    updated: 2011/05/30

  4. #4
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    Nevermind.
    120g AGA~145 lbs Haitian LR~DA Reef Keeper 2 Controller~Dual 14k 250 DE MH's~Dual Overflows~Dual 250w Jager Heaters~Dual 96W Actinics~30g Sump/Refugium~Mag 12 Return~140 lbs Reefgrade Caribsea Aragonite~BubbleKing 180 Skimmer~Phosban Reactor~GEO Kalk Reactor~Powerheads:MP40w/Seio 820/modified Powersweep 270 with Hydor rotating deflector~Digital lighting timer for moon/fuge lighting~7 stage RODI filtration~Quarantine: modified 12.5g Marineland Eclipse

  5. #5
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    leds

    i have had no problim with my leds and my grama in a 5gal frag tank with my leds about 11in. above my tank. it may be the lenses on the leds. ask the manuf. about the lenses. i would raise the light up 10in and try that for a week.

  6. #6
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    Just thought I'd mention that the fish have finally gotten used to the LEDs, I kept them at about 6" above the tank and acclimated the fish to them, gradually increasing the photoperiod. I think the main thing that helped was that I only fed when the LEDs were on... kind of forced them to brave the new light. It's always nice when a problem just works itself out!

  7. #7
    liv
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    nice, thanks for the update.
    always fun when things turn out ok :b2:

    moving.. so temporarily out of SW :b8:
    planning next tank, possibly 60x30x20 on 2x plasma.
    updated: 2011/05/30

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