The Watts per Gallon Rule!
- Thread starter Dollarz81
- Start date
I think the watt/gallon rule is useful in a very, very limited guideline sort of way. Lighting is much more complex than how much intensity you cram over a container. A coral that is 4 inches from the surface and lit by 440w of vho lights is not recieving as intense light than if it's sitting in the same place but directly under a 175w MH. There are a ton of articles and discussion forums dedicated to lighting. Some of the things I've read have been fairly straightforward and clear, others have sent me looking for a dictionary so many times that I just gave up. I have a fair idea of the lighting requirements for the the types of corals and animals that I'm interested in. I've been able to figure out that factors like depth of penetration, water volume, distance the lamp will be from the surface of the water, species requirements, are the things that truly determine what amount and type of lighting you need.
Narkon'n'more
New Member
Really if you think about it, it came out when they mostly only had VHOs to work with, and if you only have one type of light to wotty about, well the rule worked, but now we have different types so it doesn't work like it use to.
Nathan
Nathan
Without getting into the complexities of lighting, the watts per gallon rule is a good starting point for newbies and for poeple trying to get an idea on how to light conventionally dimensioned aquariums. With researching, coral selections, and every other variable I've seen that rule broken successfully a lot. Both above and below that rule.
Cameron
Cameron
Narkon'n'more
New Member
But Physh what if the person wanted to immediately jump into using MHs?
I don't know if it such a good rule.
Nathan
I don't know if it such a good rule.
Nathan
Wall, that is why I said it's a good starting point. It's def. no great. Most newbies who would delve right in would be looking for advice on MH and therefore would likely be informed.Narkon'n'more said:
It's a good starting point but hardly realistic in a lot of apps.
Cameron
Narkon'n'more
New Member
Yeah, I see your point now. Your right it is a good starting point for those that buy the tank before reading the info.
I spent 6 months getting myself informed before I bought the first item that wasn't a book.
Nathan
I spent 6 months getting myself informed before I bought the first item that wasn't a book.
Nathan
I think its a very vague rule of thumb at best. 6 watts per a gallon in a 20L is way different than 6 watts per a gallon on a 120 or 180 gallon tank due to water depth.
It really wouldnt matter much if you only put the corals 6" deep though as the light hitting them would be about the same intensity level wheather a 20L or 180. But if you own a 180 who is only going to put corals in the top 6-12 inches, I am filling that baby up!
Good point too was brought up about the watts per a gallon rule being out about the time when VHO's were the bomb. Today our halides/flourecenst lights are way better than 15-25 years ago to a point where its like comparing night and day!
While I take a lot of latitude in the watts per a gallon rule and feel its very conservative, I feel its way out dated. I have conducted test on a number of tanks with various wattage, and 4 watts per a gallon on a standard 10 gallon is marginal at best for even hardy softies and anything other than about 8-10 watts of the same type lighting was minimal for SPS/Maximas or Croceas. But then on the other hand, and I am sure I will be flamed for this, a 400 watt halide on the same 10 gallon tank which I have seen highly touted as being optimal, borders on the ragged edge of over kill. I am just waiting to hear someone saying that the new 1000 watt halides are the best on a 10, and in my opinion, I dont care what kinda clam or SPS you have, thats insaine!!!
Am I a lighting Guru, heck no! Lighting is one of the most heated and debated topics on every forum out there that deals with saltwater. Some threads so brutal I am suprised that blood wasnt spilled, over the issue.
So while I think there is a lot of room for various applications of light and still adequately light a tank and be successful, I think its well over due to do away with the "watts per a gallon rule". It fails to take in way too many variables that exist in lighting these days.
JME & MHO....
It really wouldnt matter much if you only put the corals 6" deep though as the light hitting them would be about the same intensity level wheather a 20L or 180. But if you own a 180 who is only going to put corals in the top 6-12 inches, I am filling that baby up!
Good point too was brought up about the watts per a gallon rule being out about the time when VHO's were the bomb. Today our halides/flourecenst lights are way better than 15-25 years ago to a point where its like comparing night and day!
While I take a lot of latitude in the watts per a gallon rule and feel its very conservative, I feel its way out dated. I have conducted test on a number of tanks with various wattage, and 4 watts per a gallon on a standard 10 gallon is marginal at best for even hardy softies and anything other than about 8-10 watts of the same type lighting was minimal for SPS/Maximas or Croceas. But then on the other hand, and I am sure I will be flamed for this, a 400 watt halide on the same 10 gallon tank which I have seen highly touted as being optimal, borders on the ragged edge of over kill. I am just waiting to hear someone saying that the new 1000 watt halides are the best on a 10, and in my opinion, I dont care what kinda clam or SPS you have, thats insaine!!!
Am I a lighting Guru, heck no! Lighting is one of the most heated and debated topics on every forum out there that deals with saltwater. Some threads so brutal I am suprised that blood wasnt spilled, over the issue.
So while I think there is a lot of room for various applications of light and still adequately light a tank and be successful, I think its well over due to do away with the "watts per a gallon rule". It fails to take in way too many variables that exist in lighting these days.
JME & MHO....