Upgrading from two to three Radion G5 XR15 Pro fixtures


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Jul 31, 2019
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Zug, Switzerland
Hey guys,
Last year I bought two XR15 Pro fixtures and I'm really happy with them.
My Acros on the top are starting to shadow themselves and so I ordered another fixture.

Tank: RedSea Reefer 425XL (Mixed-reef)
Currently running the two fixtures at 90% intensity. (and the fans sometimes do get noisy)

Once I install my third fixture, should I start all three at 60% intensity and go up from there to maybe 80%?
I'm kinda trying to linearly scale the par values from the BRS data sheets for 2 / 4 fixtures.
At 80% I should be in the 300 par at the top half and under 200 par bottom half? Does that sound reasonable?

I just don't want to shock my acros (top half) and my LPS (bottom half).

Thanks for the replies!

How long does it take to you to get an inch of acropora growth? (on average)

  • A couple of weeks or less

    Votes: 3 1.4%
  • Up to 1 month

    Votes: 14 6.5%
  • Up to 2 months

    Votes: 21 9.7%
  • Up to 3 months

    Votes: 37 17.1%
  • Up to 6 months

    Votes: 49 22.6%
  • Up to 12 months

    Votes: 15 6.9%
  • 12+ Months

    Votes: 7 3.2%
  • I can't grow acropora

    Votes: 61 28.1%
  • Other (please explain)

    Votes: 10 4.6%