sneeyatch
Active member
<a href=showthread.php?s=&postid=9839804#post9839804 target=_blank>Originally posted</a> by pjf
The 3x figure comes from comparing a parabolic reflector with no reflector.
Without a reflector, only the bottom third (120 degrees) of the light reaches the substrate.
The remaining 240 degrees of light (represented by the red curve above) illuminates your walls and ceiling.
Beyond 120 degrees, the shallow angle causes light to pass through the aquarium glass instead of being reflected back into the tank by the glass walls. Shallow light often “leaks†through the side glass of a rectangular aquarium and illuminates the floor on the left and right side of the stand.
Here’s what should happen when an individual parabolic reflector is used:
The upper 240 degrees of light is directed downwards. There is a small loss of light that goes straight up and is reflected back into the tube. The larger the reflector is in relation to the tube, the more effective the reflector. A narrow diameter T5 tube enhances the reflector’s effectiveness. Bending retrofitted reflectors to fit into a small area is not optimal.
Without individual parabolic reflectors, a significant portion of light is blocked by neighboring tubes or passes through the aquarium glass without reaching the substrate. How much depends on the geometry and can be determined by measuring the PAR.
Another inexpensive alternative to consider is to build a canopy with T5 components and individual reflectors. You can start with a canopy, a ballast and two tubes/reflectors. A second set of ballast and tubes/reflectors can be added later.
now, i'm not going to clown anyone for this, but if you take your drawing of the individual reflector and stretch the apex of your curve, you would have the reflector in a nova. i agree that "some" light would be blocked by the other tubes within this same single reflector, but come on - it shouldn't be enough to even make a marginal difference. i'm beginning to think that everyone here that is bashing the nova's reflector hasn't seen the reflector at all. it's not just a flat piece of reflective material, and it does continue down the interior sides of the fixture. then i start to think that even if you've seen the fixture, then most of you must think that the lamps only emit light from the bottom 180º of the lamp and really believe that the reflector is a vacuum as mentioned above.
the funny thing is, i still haven't seen the comparison par numbers either, but i'm starting to think why... everyone is so caught up in the fact that the more it costs, the better it is. in this hobby, that is usually the case - BUT apparently kodyboy holds stock in the typhoon and a bunch of others love the new jebo skimmers. you can mod a prism and it apparently can keep up with or outperform coralife's skimmers. i think once these fixtures get placed side by side with the same bulbs in each, the par differences will vary some, but not much - then everyone with these high dollar fixtures will kick themselves.
