Neptune Aquatics

different bulbs, different shimmer?

A_Lee

A_Lee

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I caught wind that different brand HQI bulbs, and different kelvin ratings are all factors in how much shimmer you get in your tank- frankly, I had no idea, I thought a MH bulb is a MH bulb. true false yes no? Can someone enlighten me as to how this works?
Does a higher kelvin rating produce more or less shimmer?
What brands of bulbs produce the most shimmer?
Also, I assume the more flow you have (in general) the tank the more scattered shimmering you'd get? or does only the surface of the water (say water flowing in the overflow) affect the shimmer?

Also, I was thinking of swooping up a 14K phoenix bulb and replacing the stock 14K current usa powerpaq in my sunpod (I don't use any actinic supplementation). Does the phoenix bulb have higher PAR?
 
[quote[I caught wind that different brand HQI bulbs, and different kelvin ratings are all factors in how much shimmer you get in your tank- frankly, I had no idea, I thought a MH bulb is a MH bulb. true false yes no? Can someone enlighten me as to how this works?[/quote]

Not having paid attention to this myself, I can only give you a round about explanation of what's going on. Whenever a light ray hits a surface that's not perpendicular to it's direction of travel it bends. The amount that it bends is based upon the index of refraction. However the index of refraction is not *A* number (regardless of what people estimate it to be), but it's a function of the wavelength of light, basically it's how a prism makes a rainbow, different colors bend more. Now depending how strong of an intensity a bulb gives out at any particular wavelength might radically change how much bend the light does, some bulbs with a heavy blue component only vs "yellower" bulbs that have different ranges of wavelength.

However all that being said, I couldn't tell you if one "color temp" of bulb gives more shimmer than another. IMO you want more shimmer make the surface water more turbulent.

And yes the phoenix bulb most likely has a higher PAR, it is one of the highest PAR bulbs (if not the highest) in that color temperature.
 
Ah, so having water on the surface constantly moving will have a large impact on the shimmering effect right Mike? More so than the water below the surface? Only reason I ask is because my cube will have quite a bit of water movement into the overflow.

Yes, I kind of like the Phoenix bulb as a stand alone bulb, though I'm still debating whether or not I should with that or a 20K Ushio. The higher the Kelvin rating the lower the PAR levels?
 
Absolutely, the reason for shimmer lines is due to the ripples in the surface (that whole non-perpendicular thing I was talking about earlier).

Yeah typically higher kelvin = lower par, however that's not always the case, you can still get a crappy 10K bulb that puts out crap for PAR.
 
Worth noting that the best shimmer comes from a point source light which is what we avoid with good reflectors. Lumenarc/bright/max etc (large) reflectors give us a lot more light, less shadows, and less shimmer. Those tiny HQI reflectors like on sunpods will give more shimmer but suck compared to the big reflectors for efficiency.
 
Yeah, I will be using a Sunpod over my cube, mainly because it is nice and compact.

Mike - so in a nutshell, and your experience, what 14k, and 20k bulbs would qualify as "PAR Monsters?"
 
What wattage? I don't have direct experience with many 20k bulbs only ran them in 150w on a QT tank after the last frag swap, that wattage alone should not be used with "Par monster"

In 250w, I think the Phoenix bulb is one of the best as far as PAR (assuming double ended bulbs you're using)... for the 20K side of thing,don't think there are many bright bulbs that are double ended. If you look at single ended bulbs, the the aquaconnects are pretty powerful (but at a huge price) as are the Radiums, if you have an HQI ballast.

Check out Sanjay's site he has the low down on how much PAR (ppfd) for a ton of bulbs at many different watts with different ballasts.
http://www.manhattanreefs.com/lighting
 
Gotcha, can't really give much hands on advice to that wattage then, other than I've looked at some number that are out there, and to get any decent par you really need to go 10k
 
yeah, after doing some reading, seems like a 10K, maybe even a little lower, will yield the best results for PAR output. But seeing as how I am not using any actinic supplementation, a 14k, or a 20k is going to be best bet because I don't dig that 10k look. But I do want to still see growth in my corals.
 
Also depends upon how deep of a tank you're talking about too. I mean don't take my word that 150w = crap because I'm comparing it against standard tank depths 18-24" which is usually your larger tanks.

If this is over a smaller "nano" sized one, then you probably can get away with the 20k range without much of an issue.
 
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