4-8 watts per gallon?

tunerX · #1 04/12/2007, 11:07 AM

I have a 95 gallon wave tank and read that the recommended light requirements is about 4-8 watts per gallon for a reef aquarium. I bought a 492 watt 2x 150 watt HQI 14000 and 2x 96 watt Actinic which gives me about 5.1 watts per gallon.

I installed the light on the tank and found that this is super bright. I was using a 265 watt compact with 6700/10000 and actinic 420/460 which seemed bright enough to me. Is 4-8 watts per gallon really an accurate scale? I couldn't imagine using a 760 watt to get 8WPG.

MercZ · #2 04/12/2007, 11:27 AM

If you think thats bright you should see some of the overdriven T5 setups or 250/400 MH with T5 supps. Its not so much the watts per gal but the setup you have and the par you put out. Like the PC's in your fixture dont put out that much par compaired to T5's, VHO'S and MH. With your current setup youll probably still have to keep more light needy corals higher in the tank than if you went with a T5 setup or had 250 MH's.

David Grigor · #3 04/12/2007, 12:01 PM

Throw the watts per gallon stuff out the window.

It's means absolutely nothing........and with different lighting technologies you can't compare one with another by using electricity input usage as a guage.

Also don't forget, what may not look as bright to the human eye doesn't necessarily mean it is true to how the coral uses/responds. Especially in the higher end K bulbs like the 14k your mention, they will look dimmer to the human eyes because we are more adpated to true daylight spectrums but the corals are likely receiving more light.

You need lux or even better a par meter to determine lighting output for comparisons.

Lastly, don't make the assumption that becuase a bulb is rated at X watts that it only uses that amount. You need a watt meter to accurately determine. Most 150W HQI are closer to 200w input and some even higher depending both the ballast and the bulb used...

How far off the water do you have the fixture? This will play a big role as well to the brightness, the closer you can get it without splashing and over heating and still get adequate light coverage the better.

The proof will be in the pudding over the next 6-8 months as you see how the corals respond/adapt to the new light.....

michaeldaly · #4 04/12/2007, 12:30 PM

I would not say watts per gallon means absolutely nothing - it is a good general rule), but many other things also have to be taken into consideration such as what type of lighting it is, colour temperature, depth of tank(most important IMO) and what you are planning to keep.

David Grigor · #5 04/12/2007, 01:29 PM

Again means nothing. Even as a general rule it's totally obsolete and very flawed due to all the type lighting choices, ballasts, spectrum of bulbs etc.

Coral placement in relation to the light is all the matters and the amount of intensity that reaches the coral is all that matters.

I can have a 400W MH on a 10bazilliion gallon tank. As long the the coral is 8" under the light it will receive the same amount of light as a coral at the same distance in a 10g tank. WPG is going to be .0000000001 and other is 40.

It may have been somewhat comparable back in the day when only NO lighting was available.

I know I'm preaching to the choir because you know all this just the original poster doesn't really appear to and putting way too much emphasis on it......

GSMguy · #6 04/12/2007, 01:30 PM

its not as bright as the sun at the equator

i run 10wpg all halide and its not too much light

my bulbs actually run at 290w per giving me a total of 11.6wpg of MH

pitogo · #7 04/12/2007, 01:36 PM

Quote:

Originally posted by GSMguy
its not as bright as the sun at the equator

i run 10wpg all halide and its not too much light

my bulbs actually run at 290w per giving me a total of 11.6wpg of MH

Same here I run 2x175 MH 10K /w dual electronic ballast and I'm thinking of supplementing it with PC atinics. The coralline algae growth its simply amazing.

skey44 · #8 04/12/2007, 02:01 PM

you should join the everything seems dimmer the longer i've been reefing club... my first "true reef light" was a 96w pc i had on a 30g and boy do those old pics seem dim these days.

tunerX · #9 04/12/2007, 05:37 PM

Quote:

How far off the water do you have the fixture? This will play a big role as well to the brightness, the closer you can get it without splashing and over heating and still get adequate light coverage the better.

I have it on the legs, that came with it, and it is about 4 inches off the glass. The glass to the water is about 1.5 inches. So I have about 5.5-6 inches to the top of the water.

I just finshed my cycle about 10 days ago. Today I bought two small LRs with some live stuff on there. If I post a pic of my rocks and tank setup with pictures of the mushrooms and other stuff would you be willing to tell me a good depth to put them based on my current light setup.

Also what is a good PAR meter?