watts per gallon rule

gasbatalla · 05/19/2010, 08:13 AM

In my local forum, they always say that light should be according to the watts per gallon rule, but i have read that this is not true. Could someone elaborate on this please

KafudaFish · 05/19/2010, 08:20 AM

That is pretty much old school thinking. Now people look at PAR instead of wpg.

I could have a tall tank say 30 inches tall with PC lighting and 25 watts per gallon but it won't mean much if I am trying to keep clams healthy. If I have a PAR reading of 250 on the sand then I know I am good even if my wpg is only 8.

sjm817 · 05/19/2010, 08:26 AM

Watts/gallon rule is ok for heaters, but not for lighting.

James77 · 05/19/2010, 08:46 AM

There are far too many variables, especially with T5 and LED, to make such a broad "rule" as watts per gallon. Types of light, temperature of light, quality of reflector, cooling, water depth and clarity, and most impotantly what critters you are keeping all dictate how much lighting you need.

A set of T5's that are just enought to keep SPS/clams could fall far short if they are not cooled. If a tank requires 750 watts of halides, 750 watts of LEDs with optic could scorch everything.

gasbatalla · 05/19/2010, 08:53 AM

Thanks everyone for the answers, any other information will be welcome also

AquaticFins · 05/19/2010, 12:08 PM

For our purposes, a watt is merely a measurement of how much power a device consumes. It says nothing about how much light is generated.

For example, a typical household 100W incandescent lamp, a 24W compact-fluorescent and a 6W LED all produce roughly the same amount of light, even though they use vastly different amounts of power in order to do so.

sedor · 05/19/2010, 01:03 PM

These days the technology in lighting has allowed for manufacturers to produce powerful lighting options that utilize half the watts the old fashioned bulbs used. Unless your talking VHO's, watts per gallon is obsolete.

05/19/2010, 08:13 AM	#1
gasbatalla Registered Member Join Date: Mar 2010 Location: Costa Rica Posts: 243	watts per gallon rule In my local forum, they always say that light should be according to the watts per gallon rule, but i have read that this is not true. Could someone elaborate on this please

05/19/2010, 08:26 AM	#3
sjm817 On Yer left! Join Date: Sep 2004 Location: Northern VA Posts: 18,777	Watts/gallon rule is ok for heaters, but not for lighting. __________________ - Scott

05/19/2010, 08:46 AM	#4
James77 Registered Member Join Date: Aug 2005 Location: Rhode Island Posts: 8,158	There are far too many variables, especially with T5 and LED, to make such a broad "rule" as watts per gallon. Types of light, temperature of light, quality of reflector, cooling, water depth and clarity, and most impotantly what critters you are keeping all dictate how much lighting you need. A set of T5's that are just enought to keep SPS/clams could fall far short if they are not cooled. If a tank requires 750 watts of halides, 750 watts of LEDs with optic could scorch everything. __________________ Jim Current Tank Info: 120g Mixed Reef and 75g Freshwater

05/19/2010, 01:03 PM	#7
sedor Registered Member Join Date: Sep 2007 Location: Charlotte, NC Posts: 4,689	These days the technology in lighting has allowed for manufacturers to produce powerful lighting options that utilize half the watts the old fashioned bulbs used. Unless your talking VHO's, watts per gallon is obsolete. __________________ Ryan

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Do wwe still use the $$$ per Gallon rule??	Mr James	Reef Discussion	27	10/09/2009 07:01 AM
18 watts per gallon in a 10 gallon mushroom community	Ryan Heitzman	New to the Hobby	7	06/13/2008 06:35 AM
Watts per gallon or depth of tank rule?	jimi thing	Lighting, Filtration & Other Equipment	4	12/31/2007 02:46 PM
Watts Per Gallon vs. Watts Per Depth	bbyatv	Lighting, Filtration & Other Equipment	0	12/24/2007 12:16 AM
What Is The Fish Per Litre/gallon rule?	Madoktopus	Reef Discussion	4	03/12/2006 02:31 PM

05/19/2010, 08:20 AM	#2
KafudaFish Cyprinius carpio Join Date: Mar 2004 Posts: 4,496	That is pretty much old school thinking. Now people look at PAR instead of wpg. I could have a tall tank say 30 inches tall with PC lighting and 25 watts per gallon but it won't mean much if I am trying to keep clams healthy. If I have a PAR reading of 250 on the sand then I know I am good even if my wpg is only 8.

05/19/2010, 08:53 AM	#5
gasbatalla Registered Member Join Date: Mar 2010 Location: Costa Rica Posts: 243	Thanks everyone for the answers, any other information will be welcome also

05/19/2010, 12:08 PM	#6
AquaticFins Premium Member Join Date: Dec 2002 Location: Michigan, USA Posts: 887	For our purposes, a watt is merely a measurement of how much power a device consumes. It says nothing about how much light is generated. For example, a typical household 100W incandescent lamp, a 24W compact-fluorescent and a 6W LED all produce roughly the same amount of light, even though they use vastly different amounts of power in order to do so.