double ended mh bulbs vs screw in type

[StirCrazy]

Originally Posted by BrainVat

Zooxanthellae use a number of mechanisms not available to plants to harness light energy from other portions of the spectrum. These include, but are not limited to UV-A rays, and are responsible for the rich coloration you see on your corals.

If we were only concerned with the PPFD over the PAR region, then we might be tempted to think that 6500k Iwasakis (189 PPFD @ PAR) are more desirable than 20k Radiums (85 PPFD @ PAR). Try it out for yourself, and you'd find that the corals under the Iwasakis generate xanthophyll pigments to protect themselves from the heat transmitted by higher wavelengths. These give off a rust brown color however, and we tend not to prefer this "look" on our corals. (Though do use lower temperature bulbs on the grounds that the corals receive more PAR light.)

This is why when I argue that DE bulbs generally give off more light, I only speak of raw intensity. Its final effect on coral growth, presentation, or other subjective visual tastes are a completely separate matter to me.

your missing the point. PPFD is another measurment reading of PAR.. they are the same. and I have seen Iwasaki tanks just as colorfull as radium tanks, and I have seen radium tanks just as brown as other tanks. takes a lot more than just light to make color, and light won't make real color on its own.

Steve

[BrainVat]

I think you're misunderstanding mine and Dr. Joshi's argument. He is saying that it is a myth that DE bulbs are always brighter than SE bulbs, whereas I am saying that it is still a good general rule for bulbs within a given brand, despite a few exceptions like that one.

[Samw]

Originally Posted by BrainVat

I think you're misunderstanding mine and Dr. Joshi's argument. He is saying that it is a myth that DE bulbs are always brighter than SE bulbs, whereas I am saying that it is still a good general rule for bulbs within a given brand, despite a few exceptions like that one.

He didn't use the word "always". That wouldn't make any sense. In studies like this, I've never read or heard anyone say that DE bulbs are always brighter than SE bulbs. What people normally say is that DE bulbs are generally brighter than SE bulbs. This is the myth (according to Sanjay). It is quite simple, all Sanjay is simply saying is that its a myth to think that DE bulbs are brighter than SE bulbs. IF he wanted to say "It is a myth to think that DE bulbs are always brighter", then he would have said it. But he didn't. What he is saying is that its a myth that DE bulbs are generally brighter than SE bulbs because his data shows that SE bulbs are generally brighter than their DE counterparts.

And that XM graph is not an exception. It seems to be the rule. Did you see the other 5 random graphs? They have the same results. Can you tell me again how you measure intensity? You haven't even shown 1 graph yet where the SHIELDED DE bulb of the same brand is brighter than the SE bulb. There might be 1 or 2 but they aren't easy to find. I haven't found it for 250W ballasts yet. I'm sure if I spend another 10 minutes, I might find one.

[Samw]

http://www.reefcentral.com/forums/sh...e+and+brighter

So here, 1 out of 14 tests had the DE as being brighter. Note that these are UNSHIELDED DE tests. Normally, the DE output would be even lower under regular applications (due to the glass shield). Its hard for me to believe that DE's are generally brighter when only 1 out of 14 have higher output and that 1 DE that was higher was unshielded even. When the DE's are shielded, all 14 SE bulbs are brighter.

[Samw]

Originally Posted by StirCrazy

thanks Sam, that page wouldn't work for me.

Steve

Hey Steve. Are you using Firefox or Mozilla or using a MAC? Apparently, the page only works under IE on Windows. If you are using IE, did you select the wattage listbox first?

http://www.reefs.org/phpBB2/viewtopi...306&highlight=

BTW: Doesn't anyone else besides Brainvat, Steve and myself have a position on this? What about some of the other veterans??? The data shows that SE bulbs are generally brighter. Is the data wrong? Do the graphs lie? Is PAR not a good measure of light output or intensity? What is better than or more relevant to corals than the measure of PAR or PPFD. Are there any links at all with data from research that shows DE's of the same brand are generally brighter than SE's given the same color temp and ballast?

Could people start jumping in and verify that I am not blind here and that the graphs and data on the website do indeed indicate that the SE's tested had higher light output than their DE counterparts? Am I out to lunch cause everyone else is awfully quiet. I am constantly rechecking the data and graphs thinking that I am reading it wrong since someone keeps telling me that the DE's are brighter based on the data on that website.

.

[StirCrazy]

this whole thing got started with the 150 watt DE, putting out a higher PAR level than a 400 watt SE. this was Sanjay's first test of them and the reason was he used a mini pendant for the DE and a bare bulb for the SE. so the DE had the benefit of a reflector. What he later found out is the reflector design of the DE was such that it caused a more intense output in a small area. so in essence it was better at focusing the light. the problem was that the light over a 2x2 section was lower than normal except for the smaller focal spot. When they started testing the bulbs with no reflectors then they found the SE bulbs put out more PAR/Light than a DE which only makes sense if you look at the shape and design of the bulb.

Steve

[stephane]

I been bash many time for this Steve

I know it since long time SE are supperior bulb in any way but...it's more paying to sell DE.

Ho! By the way magnetic ballast are the best

[EmilyB]

Can someone translate that for me please ?

I have just bought HQI ballasts and am trying to keep up.

[StirCrazy]

Originally Posted by stephane

I been bash many time for this Steve

I know it since long time SE are supperior bulb in any way but...it's more paying to sell DE.

Ho! By the way magnetic ballast are the best

hey Stephane, good to see you again.

Steve

[stephane]

HI Steve

The store and French forum board take a lot of my time but when I have couple of minute I came here read a bit wath happen in the Ouest

See you