yet another MH question

Good question Ice... I would like to know too...

 

PAR is how much actual light is in the tank and how bright and powerful it is. thats the bets explaination i can give. would anybody else like to try.

 

PAR: A measure of light intensity in the useful wavelength spectrum

 

Photosyntheicly Active Radiation (PAR) is a measure of the amount of radiation capable of driving photosynthesis striking a unit area. It is given in the units of micro moles per meter squared per second (umol/m2/s). And is used interchangably with Photosynthicly active Photon Flux Density (PPFD).

And another one, because it appears a lot of people don't understand it. Actinic reffers to a light source of all possible spectral outputs, and it does not have to be blue. And it is not blue light that makes coral glow, it is the Actinic which will make anything containing chlorophyll glow. Though, it may not be precivable to us.

 

[quote author=m_lacom99 link=board=lighting;num=1099320951;start=15#27 date=11/01/04 at 12:04:26]ok Matt.. i dont "need" them but they cant hurt right???  OK if you were me and you had a 55 gallon long (48"Lx14"Wx18"H) what would be your lighting setup???[/quote]

I'd probably just go with a 250 watt halide setup. 55 gallon tanks are not very tall. If I could get a good deal on a complete hood with actinics I might bite, but I'd probably just get a pendant and may or may not add actinics depending on how I like the halide bulb. I like open tops with pendants - less heat, but more evap. My preference though.

[quote author=Ice link=board=lighting;num=1099320951;start=15#29 date=11/01/04 at 12:22:24]
I am very new to MH lights. Matt you said the par of 6500k is extremely high...
[/quote]

Peter not all 6500k's , just the Iwasaki. There are plenty of crappy ones out there that come stock with some setups. Mia culpa!

 

[quote author=birdlady link=board=lighting;num=1099320951;start=0#4 date=11/01/04 at 10:42:31] [smiley=biglaugh.gif] Yeah, Fletch, you're using your tank as the main room light, eh!  Get it fired up yet?[/quote]

Not yet I have the light but I still have to get the bulbs I am getting a little worried that this is going to be tooooooooooo much light [smiley=hehe.gif] ;D 8)

 

it's not gonna be too much light, trust me. You have a 75 gal. tank if i had your lighting it might be too much. u will love it.

 

Hottie the only difference in a 55 and a 75 is the width of the tank If it was a 90 I wouldn't be concerned as the 90 is deeper than the 55 and the 75
You have 9 watts per gallon which is great but I am going to have 13.6 watts per gallon

 

Maybe you right hottie :-/but I am just getting a little concerned I don't want to fry everything in my tank :
Does anyone else have an opinion

............ John

 

u wont fry everything in your aqarium. u would need a lot more than those lights to fry everything in your tank.