What is the right amount of light?
Printed From: Utah Reefs
Category: Main
Forum Name: General Discussion
Forum Description: Posts that don't fit in any of the other categories.
URL: http://www.utahreefs.com/forum/forum_posts.asp?TID=82824
Printed Date: May 11 2025 at 3:23pm
Software Version: Web Wiz Forums 12.03 - http://www.webwizforums.com
Topic: What is the right amount of light?
Posted By: Mark Peterson
Subject: What is the right amount of light?
Date Posted: July 07 2017 at 3:29pm
|
There is something that concerns me that may be happening in the hobby these days. Below is a graph from the lighting schedule of an Aqua Illumination Hydra 26HD program found posted on reef2reef. I believe it was posted as an example of an acceptable lighting schedule. My concern is threefold: 1. the intensity of the blues is set too high; 2. the effective photoperiod is set too short; 3. the spectrum of light may actually be inadequate. What's your opinion? Regarding my comment #3: The number of LED's of each specific color that is included in these fixtures is built that way to account for the needs of coral as well as the "look" required by the whole range of hobbyist individual preferences. I'm just wondering what really is the best combination of these wavelengths for coral and where is the point where individual preference may have a negative effect on the needs of the coral? Aloha, Mark  ------------- Reefkeeping Tips, & quick, easy setup tricks: www.utahreefs.com/forum/forum_posts.asp?TID=9244 Pay it forward - become a paid WMAS member 
|
Replies:
Posted By: sleepingdeep
Date Posted: July 07 2017 at 3:51pm
| pics not showing... so.. |
Posted By: Hogie
Date Posted: July 07 2017 at 3:51pm
| My opinion is the graphic or link should work better. |
Posted By: Mark Peterson
Date Posted: July 08 2017 at 5:53am
 ------------- Reefkeeping Tips, & quick, easy setup tricks: www.utahreefs.com/forum/forum_posts.asp?TID=9244 Pay it forward - become a paid WMAS member
|
Posted By: Mark Peterson
Date Posted: July 08 2017 at 4:43pm
|
The company claims the Hydra 26 fixture operates at 90W so may we assume that each of the 26 LED's is rated at 3.46W? If so, the table below is illuminating. (pun intended  )UV 40% of two LEDs 6.92W X 40% = 2.77W /57.75 total watts = 4.8% of the total Violet 55% of two LEDs 6.92W X 55% = 3.81W /57.75 = 6.6% RBlue 105% of six LEDs 20.6W X 105% = 21.63W /57.75 = 37.5% Blue 100% of six LEDs 20.6W X 100% = 20.6W /57.75 = 35.7% Green 10% of two LEDs 6.92W X 10% = 0.69W /57.75 = 1.2% Red 15% of two LEDs 6.92W X 15% = 1.04W /57.75 = 1.8% White 35% of six LEDs 20.6W X 35% = 7.21W /90 = 12.5% _______ 57.75W Of 57.75 Watts the intensity of the UV, Violet, Red and Green LEDs are fairly insignificant compared to the Royal Blue and Blue which make up ~73.2% of the total light emitted from that fixture. Only Cool White is also significant at 12.5% of the light emitted. Where to go from here?  ------------- Reefkeeping Tips, & quick, easy setup tricks: www.utahreefs.com/forum/forum_posts.asp?TID=9244 Pay it forward - become a paid WMAS member
|
Posted By: Wrogers
Date Posted: July 13 2017 at 7:48am
|
Hello Mark, I was wondering how this light set up is working for you.. We use the same light on a 50 gal cube. Reds and green to my understanding are more for us then our tanks. Everything else looks about the same as our set up we run our UV lower.. Have you did a Par test ? How are your corals doing?? We did map out are tank on Par, this unit puts out some good light.. Would love to hear what you have done and how your tank has responded to changes you have made.. We are always looking to improve our set up :} Thank You, Will
|
Posted By: Mark Peterson
Date Posted: July 13 2017 at 9:47pm
|
Maybe I wasn't clear. That schedule is one that I believe to be inappropriate. I do not use it. It was sent to me by a friend, new to the hobby that recently sunburned all his coral and the Coralline Algae on the tops of LR. Many of the coral received a fatal dose of bright light (mostly blues set at close to 100%) in just a few days. His coral started dieing a week after the overexposure and kept dieing for two weeks. There is very serious trouble with this blue light, formerly referred to as Actinic blue, that hobbyists may not realize. It is the fact that our eyes do not recognize the intensity of this bright blue light. It is burning our coral but we can't see it. We only see the effect after the sunburn. Copied below for your benefit, is what I said in the OP about the problem I see with that pictured schedule. I was wondering if anyone else sees the same problems that I see: 1. the intensity of the blues is set too high; 2. the effective photoperiod is set too short (with sunrise and sunset ramping set way too long); 3. the spectrum of light may actually be inadequate Aloha, Mark P.S. It's very difficult to get an accurate PAR reading of LED lights, because they emit such a narrow band of the complete spectrum. On!y the newest, high price, top-of-the-line PAR meters can give an accurate reading. Red, green and white, are not just for our eyes. The white LED's in these Hydra and Prime fixtures probably emit some red and green too. In shallow water, where many SPS coral live, coral are exposed to a fuller spectrum, including UV. These days we don't bring coral directly from the ocean to our tanks. Coral we see today has been grown under artificial lighting, typically less intense than in the wild. Having been exposed to all the different types of lighting this hobby has used, and finding MH lighting to be a standard to which we often compare, I found my recent installation of a 150 W 14000 K MH and a Hydra 26 on either side of a tank to be quite revealing. To make the LED light match the MH, the violet, blues and white were set in the high 30% intensity with UV, red and green about half that. ------------- Reefkeeping Tips, & quick, easy setup tricks: www.utahreefs.com/forum/forum_posts.asp?TID=9244 Pay it forward - become a paid WMAS member
|
Posted By: Mark Peterson
Date Posted: July 14 2017 at 8:18am
|
Further thoughts on this subject. The length of exposure is as important to coral as is the intensity. This fact has been well known in the hobby for years. Since we want to look at our tanks from sunup to way past sundown, it's useful to set the intensity at a moderate level yet have it shine from morning until we go to bed. This delivers the same useful "quantity" of light energy, spread out over a longer photoperiod. Taking between 1/2 to 1 hour to ramp up (rather than 4 hours as in the schedule pictured above, is also more useful to the coral. There is another reason to run the channels at less than 50% intensity. LED's lose intensity about 5%/year before they either burn out or just glow. This means after 5 years they are only 75% as bright as when we bought them. Having the ability to increase the power can keep them shining bright enough on our tanks for, hopefully, 10 years or more. Just my 2 cents.  Aloha, Mark ------------- Reefkeeping Tips, & quick, easy setup tricks: www.utahreefs.com/forum/forum_posts.asp?TID=9244 Pay it forward - become a paid WMAS member
|