Overdriving lights.

[StirCrazy]

Titus, that I have talked about by use of a PAR meter.. it measurs light waves from 350nm to 700 nm (photosynthic light range. which is the real importance in a reef) so with this you can compare any bulb to any ballast. if you look at the Post I made last night to Darren I have found instructions on making your own, and also a company in edmonton who sells then .. as I will be in edmonton over the christmas season I will check that out to see how much they are.

Steve

[titus]

Hello Steve,

Maybe you can post a price on the board to let us know how much it is when you are in Edmonton.

Are you going to check out the fellow reefers in Edmonton? I have no idea of what's the story over there but the LFS don't keep too much stock over there.

Titus

[StirCrazy]

hmm well I think Edmonton is going to be a whirl wind tour, I am leaving here on the 19th getting there on the 20th.. I have to be in a different town for the 22nd (my grammas) then back to leduc for christmas.. hmm maby I should just stay home LOL. but ya I was thinking of checking out a few fish stores while I was there.. any one know of good ones in Edmonton?

Steve

[reefburnaby]

Titus,

What would the spectrum of the lighting system tell us ? I thought what matters most is the intensity that a coral receives or lux.

Isn't PAR calibrated for green leafy plants...but not for corals ?

- Victor.

[titus]

Hello Steve,

There aren't many LFS in Edmonton. There is one in West Ed Mall but it's pretty lame. They are mostly into dog stuff. Then there is one very close to the old garrison (Griesebach, I call it greese ball lol) and they have the most saltwater fish. It's in a guy's basement but it's much bigger than J&L. And then there's this one called Aquarium Illusion (the best one I found) and make sure you check their custom tank photo catalogue. But even with these people, they have pretty basic system for salt water customers as well unfortunately.

Victor,

The spectrum analysis tells us a number of things. First we can tell if spectrum shifts occurs over time, or with overdrive, electronic vs tar ballast, etc. Second, we can tell what type of light the bulb is producing. This is good for running a correlation of spectrum response vs corals' health and build a good database. Third, it's a good way to integrate for power.

Titus

[StirCrazy]

the Algae in the corals use the same wave length as plants (and a bit lower) plants the usefull is about 420 to 680nm the PAR meter I am interested in is from 350nm to 700nm, but from what I have been reading, the PAR used by corals mostly is the 350 to 450 range, but that is only deep water coarls.. shallow water coarls will probably still use the full PAR range as they get full light at the shallow depths not filtered to the degree that most people simulate in there tanks. but it does look cooler [img]images/smiles/icon_biggrin.gif[/img] . So far everthing I read say PAR is the most important measurment of light on a reef and it is also a measurment that holds true no mater which bulb or ballast or how much power you are trying to put through the light.

Steve

[titus]

Hello Steve,

I know what you mean. But the PAR meter only tells you the total energy of all light within the 300 - 700nm range. It doesn't give any clue to the spectral shape/distribution of energy "within" this band.

It is important for corals and the most meaningful, as compared to simple lux measurement, due to the meter's sensitivity to the range of light that algae responds to.

But as we know, different corals require different spectral shapes. It is best if we can somehow qualitatively log down the correlation between coral growth vs type of light (ie spectral shape).

And I'd have to disagree with the constant spectral shape for different driving intensity part. Everything in this world is non-linear. I have a gut feeling that spectral shape changes as the bulb is subjected to different driving method/intensity.

Titus

[StirCrazy]

Yes I agree with you Titus on different power shifts the spectral band, but to my knolage (and I may be wrong)from 6 years of planted fresh tanks and everything ihave read in the last year on reef tanks (ya a year is how long I have been planning things so far, call me obsessive) but the spectrum only shows you the peeks in each light color so you can tell if you are getting a output in the 350 to 450nm range. now what you say about as the bulbs burn out the spectrum shifts but this gos to exactly what I was saying as it shifts it shift higher (fro a actinic as the coating that breaks down is what makes the lower wave lengths) so now instead of a large 350 to 450nm (PAR) it is reduces as the majority of the light has switched to a 400 to 700nm range. this is why the corals will not do as good as they are adapted to the lower end of the PAR range. but if you take your old bulbs the house plants would love them [img]images/smiles/icon_biggrin.gif[/img] [img]images/smiles/icon_biggrin.gif[/img] Also there is a difference between diferent corals and there requirments, deep watter coarls need the lower end of the par whare shallow water coarls will probably need the higher end of the par range, but take for example people that are running 10000K MH and that is it.. they have no Actinic addition but the PAR from the MH is so intence it supplies everything the need.

as for the linerarity I total agree.. but with one exception.. out put will be liner up to a point then it will go not linier (thins happens for lots of stuff in nature but while we are on this if the color changes when overdriving then in the same token it should change when underdriving so using VHO bulbs on IceCap might not be the corect spectrum the bulb was designed for either.. and when running them with NO bulbs you are over driving so the spectrum couls be changed again.. unless it is liner to a point then it starts to drift. so who knows.. I can get a PAR sensor for under 200.00 and a light meter for 30.00 but a spectrum analizer is big bucks so I can't aford that.. but I will talk toa few people who are in university and see if they have one and can rund a coupld tests for me.. who knows maby they do and will..

Steve

[titus]

Hello Steve,

Yeah it would be most interesting to see how the spectrum change as the bulbs are subjected to different driving means. So it'd be awesome if we can have the bulbs tested by someone.... somehow.

Titus

[DJ88]

Hey, Don't look at me. [img]images/smiles/icon_wink.gif[/img] I have enough to do.. lol

kidding

It would be neat to see tho.. It seems we have opened a huge can o worms on this board with this lighting topic..