in one form of green and a couple Orange.
the point is that I can take my PAR meter and put it 2" from a 250 watt HQI and it is still less par than Victoria gets in the winter on a rainy day.
all those charts on photo inhibition are great, but they are all missing one important piece of info (I just spent the last 2 hours reading and trying to find it) time, so if I shine this light on my corals how long until i reach this magical point?
this is very useful as what it would allow you to do is run some lower powered lights like T5's for the bulk of the day and then just have you MH come on for 2, 4, 6, or what ever time is required to reach the saturation point which could potentially save money.
I have been following these articles for years, I believe they started coming out in 02, but some of the others are 04. they all say the same thing and nothing at the same time. take this scenario for instance. you have a 30" wide tank, that is 18" deep and 12" wide (just picked that size as it is what I am building) I am going to run two T5's for actinic which will run 12 hours a day. I am looking at running a 250 watt SE bulb driven by an electronic HQI ballast. the bulb orientation will be in the middle of the tank front to back. and run 8 hours a day
Ok do you believe that if I take corals and put them all over that tank that they are all going to reach saturation? I would guess that it will be less than 10% of the tank is going to receive enough light to do that.
I enjoy reading the articles on line but remember that none of these have gone through peer review and that most of them are rehash of several older documents in the authors opinion. Not to say they are wrong, but we are only seeing a narrow chunk of info here. If you want to dig around there are several other good articles on lighting including a few on how to increase the amount of light in a tank with out reaching the saturation point by cycling the lights on and off for periods of time. this one formed the basis of the way I do new light acclimation and I have never seen better results. If I didn't have to buy a new computer as my old one had a melt down I would be able to give you links but they are lost to me and I haven't had the time to re find them.
another thing to consider, for the bulk of people who upgrade there lights have you ever heard anyone say "I have to much light" or "my coral growth slowed down when I put the 400 watt radiums on"?
when I started my last tank, lighting was a mystery.. Dana and those were not doing any reporting or anything at that time so we didn't even have basic articles to re-fur to.. at the same time I don't think it is a realistic set up that blasts a 400 watt iwasaki over a 12" deep tank, maybe I am wrong
info on lighting has come a long way in the last 9 years which is good. but there are new things that are more important than, which light and do I have to much, like water flow. this is probably the most overlooked thing in reef tanks and the hardest to set up properly, but I see there are a few articles out on it now which is good.
Steve