Let there be light!

[stephane]

I have 1170 on a 130 gal. it make me 9:1

[coldincanada]

I have 1500W over a 75 gal. That's 20:1.

Jay

[DJ88]

As an FYI to all you mathemeticians here.. ;) :D

Actinics really don't provide the lighting that a regular lamp or bulb creates. I'd hazard a guess to say that the Actinics most here in this thread are adding into their wattage totals aren't really a good indication of how much light energy you are putting into your tanks. Anyways to sit and compare the wattage of a MH to the wattage of a VHO or PC is like comparing apples to oranges. Watts per gallon as well isn't that good of an indication of light energy going into a tank. Jamie is running 2x250W HQI's which kick 2x250W Iwaskai's butt from here to the north pole.

I just measured the lumen output of three 95W VHO Actinics and it barely put out 3000 lumens at 4". As well the PAR of those three is only 100. Not a lot is it.

They put out energy yeah.. but in only one wavelength which means you are putting a whole lot less energy out than an identical lamp having a kelvin temp of say 10KK.

With that said.

16.2:1 :D :D Beat ya Titus..

You're fourth now Mason.. :D :D

[ 20 May 2002, 10:12: Message edited by: DJ88 ]

[reefburnaby]

Hi Darren,

If significant amount of actinics is used in a reef, then it can be used more readily than other wavelengths. There is more energy per unit in blue/purple wavelengths than there are in red/yellow wavelengths, so you don't need as much blue to be as effective as a red. On the other hand, it takes more energy to generate at a specific intensity of blue than red...so it all balances out [img]smile.gif[/img]

As for your lumen measurement...it probably isn't accurate since lumen is measurement of instensity centred around one particular wavelength (green). The PAR measurement...have you taken in to account the inaccuracy of the measurement at blue/UV ? Some PAR sensors are off by as much as 50% in the blue spectrum.

- Victor.

[StirCrazy]

Originally posted by DJ88:
I just measured the lumen output of three 95W VHO Actinics and it barely put out 3000 lumens at 4". As well the PAR of those three is only 100. Not a lot is it.

<font size="2" face="Verdana, Helvetica, sans-serif">was that 4" in air Darren? and were they old bulbs? that seams very low especialy at 4". at 24" I am getting a PAR reading of 156 with two 96 watt PC's (one new 10000K and one 5 or 6 month old 6500K) I know PC's are more intence than VHO but I didn't think it was that it would be that much of a difference. If I turn on my 3, 30 watt NO actinic bulbs my PAR jumps to 180.

So, to re-enforce what Darren had said yes actinic lighting does make a difference but it is small, and definatly cannot be compared to full spectrum lighting

Originally posted by reefburnaby:
Some PAR sensors are off by as much as 50% in the blue spectrum.
Victor.

<font size="2" face="Verdana, Helvetica, sans-serif">Hey Victor, the PAR sensors Darren and I have UNDERSTATE the amount of energy in the lower part of the PAR range, but it overstates the higher end of the PAR range. when it is ballanced out ir is a fairly accurate repensentation of the total average amount of PAR (380nm to 700nm).

Now, one thing I must say is that "watts/gallon" means absolutly *{squat}* and is a horable way to compare lighting. what counts is the intensity at a specific point in your tank. now to show why watts/gal is useless lets say you want to obtain a PAR reading of 275 at the bottom of a 24"x 24" x 24" (60gal) tank well one 200 watt Iwasaki would be there (I think) but you could have 8, 75 watt VHO bulbs on your tank and never get that high of a reading. so the MH route has a total of 4.1 watt/gal whare the VHO tank has a rating of 10 watt/gal but never comes close to the amount of light the MH tank has.

Steve

[ 20 May 2002, 13:13: Message edited by: StirCrazy ]

[DJ88]

Yes I have taken that into account Victor. I was trying to pass on that Actinic lighting's output(intensity or energy) is not as high as a full spectrum lamp. Nothing more. Even with your own eye you can see that an Actinic lamp doesn't put out near the intensity that a full spectrum lamp does. I could have said that but chose to try and give a small illustration with some numbers.

[DJ88]

Steve,

I am getting a PAR reading of 156 with two 96 watt PC's (one new 10000K and one 5 or 6 month old 6500K)

<font size="2" face="Verdana, Helvetica, sans-serif">All three were actinics. Not 10KK or 65KK. NO full spectrum lamps at all.

[StirCrazy]

ahhh ok that explains it [img]smile.gif[/img]

Steve

[Samw]

Originally posted by canadawest:
Well I've joined the ranks of those who strive for sunlight in their tanks....

I finally got MH over my reef!!! :D

<font size="2" face="Verdana, Helvetica, sans-serif">Right on.

So did you get any SPS? Acropora?

[canadawest]

No new SPS yet Sam. I moved my Brown Montipora Digitata underneath the Iwasaki lamp to see if it would change colour or not. Growth has not been an issue, as it has been growing excellent under the VHO lighting.

I also positioned my T. Maxima directly underneath the Iwasaki to make it more happy, and see if it experiences any colour changes. Although it also has been growing excellent under the VHO lighting, and retaining it's deep purple colouration with neon blue spotting. (Has grown from less than 1" to just over 3" in 9 months)