Recommended Watts per Gallon?

[SeanCallan]

I'm just curious if there's an easy formula, say 2.5w per gallon.

Anyone know?

[Heinz]

actually not, it all depence how deep your tank is,

[ReefRockerLive]

I'm running 12.37 watts per gallon on a 75g and none of my corals seems to react negatively.

[fkadir]

I believe the watts per gallon formulae is no longer effective. Rather, the wattage depends on how deep your tanks are. Relatively shallow tanks can get away with 150w for SPS, the deeper the tank, the more penetration punch (aka wattage) would be required. IMHO

[SeanCallan]

How about on a 12'' tank? How many watts do you think would be needed to grow some basic SPS?

[TJcop]

I would say 250w MH's...but again, this depends on what corals, where in the tank they are placed, how high the lights are off the water...
But, in a general sense, I would think 250w bulbs would be fine.

[Brad Villeggiante]

I have a 40 gallon and I am running 640 watts into it.

[fkadir]

How about on a 12'' tank? How many watts do you think would be needed to grow some basic SPS?

I have a 30" deep tank and Im running 250 watters, keeping SPS in the top 2/3 of the tank (up till about 20") with the rest occupied by LPS etc etc. Works for me.

[mesocosm]

Greetings All !

I'm just curious if there's an easy formula, say 2.5w per gallon.

Anyone know?

The current mainstream hobbyist literature presents this kind of perspective ...

"As with any light source, the correct amount of light should be estimated for the tank size and depth, and in consideration of the requirements of the various types of corals. In the past, the general rule of thumb was to provide 3 - 5 watts of light per gallon. As with any such recommendation, there are problems with accepting this as absolute gospel. Not all light sources emit the same amount of irradiance, or PAR (photosynthetically active radiation), per watt, and the point source of metal halides penetrates deeper tanks much more effectively than fluorescent lights. Perhaps obviously to some, another reason that "watts per gallon" is a bad measurement is in terms of total irradiance. ... This becomes especially true with the increase in the number of people keeping smaller reef tanks ... ."

Extracted from:
Aquarium Corals. Selection, Husbandry, and Natural History.
2001, Eric H. Borneman, TFH Publications, Inc., P.332.

And ...

"First of all, there is no one "best" lamp (fluorescent verus metal halide) for the aquarium. Lighting hardware is to be determined solely by the needs of the invertebrates and the depth at which you keep them. For that reason, you will not hear a "watts-per-gallon" rule of thumb touted loudly here. Fluorescent lamps can grow "high light" corals every bit as well as metal halide lamps, but they simply cannot do it through the same depth of water. Conversely, more light is not better than less, as has been the trend with the dreadful popularity of 400 and 1000 watt metal halides over shallow aquaria (less than 30"/75 cm)."

Extracted from:
Reef Invertebrates. An Essential Guide to Selection, Care and Compatability.
2003, Anthony Calfo & Robert Fenner, Reading Tree and Wet Web Media Publications, P. 120

Heinz ...

fkadir ...

...but again, this depends on what corals, where in the tank they are placed, how high the lights are off the water...

Indeed.

TJcop ...


As our awareness of the diversity of the photobiology requirements and preferences of our coral specimens grows, it seems to me that we will be compelled to abandon many of the "easy" ... but increasingly useless ... "rules of thumb" that have dominated the North American marine ornamental industry during the last 20 years. PAR and PSU guidelines ... and ... if we're exceptionally lucky ... microEinsteins ... will eventually replace the current industry "guides" and units.

Bizzare ... I know. But consider how crazy it was a brief 100 years ago to suggest that one day men would walk on the moon, and that only little girls would have horses ... or, more recently, what dangerous nonsense it was to suggest that bacterioplankton filtration had a legitimate place in SPS husbandry.

... hehe ... ... sorry for the rant ...

JMO ... HTH ...