Actinic LED supplement advice needed

Discussion in 'Equipment' started by psidriven, Nov 20, 2013.

  1. psidriven

    psidriven Guest

    I have a 250w lumenbrite pendant over my 21 inch cube'ish tank. The pendant is an octogon that is 16x16 inches. It has an unknown bulb that produces light similar to phoenix 14k.

    I'd like to add some actinic supplement to get a little more pop, but am still confused by the led ratings, etc. What led combination would be equivalent to two 24 inch actinic t5's? I'm considering the 18 led rapidled dimmable actinic supplement kit with 12 rb and 6 uv. This kit comes with two drivers and I would run 12 rb on one driver and the uv on the other driver so I can adjust the color as needed and for sunset/sunrise as well.

    Next question is how to mount the leds and in what fashion to the pendant. Either 1 row of 9 leds on two sides or 1 row of 6 on two opposite sides and 1 row of 3 on the two other sides. Figure the leds come with 90 spread and by tilting the rows inwards, there will be enough overlap for the entire tank. Is this a safe assumption?

    Two rows of 9 is easier but will the spread/coverage be satisfactory or is the 4 sided that much better?

    Thanks in advance.
     
  2. HiFidelity

    HiFidelity Guest

    talk to neuro he has something like that on his 250
     
  3. bluprntguy

    bluprntguy Webmaster

    To avoid disco effect from the LED's, you'll want to group the different colors together in a cluster instead of spacing them out along a line. The further they are spaced out, the more you see the different colors as "shadows" in your tank.

    The general recommendation these days from the LED gurus seems to be a combination of Royal Blue, True Violet and Hyper Violet LED's. This is where most LED light manufacturers are heading (http://www.advancedaquarist.com/2013/8/review). LEDgroupbuy has all of these colors available. I think you could run the True Violet and UV from the same driver.

    If you are just looking for supplementation, four clusters of (2)RB, (1)UV, (1)TV should be more than enough on a 21" square tank. That would give you 16 LED's total and 48 watts max. For reference, my 12" x 24" tank has 20 LED's in the AI hydra fixture and 85 watts total and it runs at about 40% max (or 34 watts) and it's the only light I have.
     
  4. sfsuphysics

    sfsuphysics Supporting Member

    FYI, the UV will not show up at all when the halide is on, the amount of fluorescence it'll do compared to everything else will be negligible. However when you have a time period when they're the only lights on you will see a dark tank with glowing corals (assuming the corals have fluorescence pigments).

    I think either mounting method would be fine, if you have 2 rows of 9 you're essentially doing 2 rows of 6 royal blues, and 2 rows of 3 actinics, they're just on the same side. With 60 degree lenses on the royal blues you should be able to get a bright accent, although I still question if they'll make much of a difference compared to the 250watt halide. I would probably not put any sort of lenses on the violet LEDs though, there are too few of them and they're basically to give that "actinic" early morning/late night look.
     
  5. psidriven

    psidriven Guest

    thanks for the reply and info. i'll take a look at the aa link.

    another idea is 4 clusters with 1 cluster at each of the 4 corners instead of rows on the front and back. figure this would move the leds inward more. would this give a better, more even spread? a side goal is light up the sides of the corals and reduce shadowed areas that eventually turn white or die off.
     
  6. bee505

    bee505 Supporting Member

    I was on the same boat, wanting some additional pop to my corals. One of reasons why I didn't go with the dimmable LED Actinic Supplement kit from Rapid LED was because it didn't have a mounting or hanging kit. I think 12 royal blue will be more than enough for your tank. for your tank, I think I would run 2 strips angled with 90 degree optics. That way you will get the spread you need. Another reason why I didn't go with the DIY kit was because I didn't have a solution to hide all of the wires. So that's something else to consider. I ended up buying a reefbrite strip.
     
  7. psidriven

    psidriven Guest

    Bee505, didn't see any 90 degree lenses available on the rapidled site. what is the spread of the led without the optic/lens? thought they were already 90 degrees.
     
  8. sfsuphysics

    sfsuphysics Supporting Member

    LEDs typically have a spread of roughly 120° without lenses. Although that's just a full width half max spread, basically most of the energy is in that angle, there still is energy outside that though.

    I don't use any lenses on my violet because I'm not concerned with penetration, it's basically there to make the tank look purple and to give the corals some pop. But if you have a small footprint tank then lenses could be useful.
     
  9. psidriven

    psidriven Guest

    mike, thanks for the info. learning about leds is like learning a new language. puck this, pad that, oh mA.....
     
  10. neuro

    neuro Webmaster

    I was doing a search on reefcentral, and after some digging around, I don't think anyone has a definitive answer to get (identical) t5 actinic replication in leds. I know I said actinic, but t5 supplementation also comes in other similar hues that people really like, so I'm not sure if there is an easy way to get a spectrum that person A vs person B considers a decent actinic.

    If I had a choice, I would have mounted additional leds on all sides of my hood. There are spots that my actinics does not cover.
     
  11. psidriven

    psidriven Guest

    neuro, thanks for the feedback. i'm thinking of going with 24 leds so i can have 3 leds on each of the pendants 8 sides for decent spread. you think using 80 degree lens and tilting the leds inward will over good coverage or should i go tighter with the 60 degrees? perfect timing as rapidled is having a bf sale on the ultra premium kit. i just messaged them if they can do solderless upgrade with the discount.
     
  12. neuro

    neuro Webmaster

    ahh that's a tough call, and I wish I could tell you but I'm not a pro. I would probably model the spread in sketchup or whatever CAD/modeling program you have to give you peace of mind. I mentioned before that Aquatic Collection is doing something like this. I think he's angling his leds using a bracket, and he only has them I think on two sides of his rectangular hood. I don't know if he's still using this setup since they recently remodeled and I haven't been back. He can offer advice if you ask. He's a nice guy and he put that setup together himself.

    But anecdotally, I would agree that angling them inward is probably what you'll want to do based on my assumptions of your tank. My setup is spotty in some areas, and it's not angled since the concentration of leds is near the center-top of the tank. However, I do think 80 degrees will be what you want for the size of your tank and you may want to hover between 15-35 degree angle. Mike or Vince can give you suggestions if you ask. Still not sure if you'll get enough penetration into the center of your tank, but I think it'll be OK. (I'm trying to imagine what you're doing on my own cube)

    You may want to also consider PAR readings of folks that have setup something similar. I wonder if it may influence your decision on how much leds you'll actually need. I would think that 24 leds is a lot of light driven at more than 80% if you already have MH--but I'm not sure myself because I haven't measured PAR. I might see if I can borrow a PAR meter and get back to you.

    and jeez, thanks to you, I now know how lucky I am to be restricted by the kind of hood I have.

    I think maybe you'll need 4 drivers total also for 24 leds (assuming you're going B/RB)....
     
  13. psidriven

    psidriven Guest

    well, i took advantage of rapidled's tday sale and picked up a 24 (16rb/8uv) solderless led dimmable kit and 2x 18" drilled/tapped heatsink. wish me luck.
     
  14. sfsuphysics

    sfsuphysics Supporting Member

    Good luck, and good choice with the solderless. I've spent enough time crouched over my work bench soldering little tiny pads with an iron that spending an extra 25 cents just to plug in a wire (that they give too!) was way nicer!.
     

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