<a href=showthread.php?s=&postid=14376760#post14376760 target=_blank>Originally posted</a> by rEd86
Great stuff Marc. I like the idea of measuring PAR around specific corals - especially the ones that are doing well. We'll have to figure out a way to log that info and build something that shows PAR ranges for corals. (and maybe flow data as well) If only you knew of someone that could do that stuff... :idea:
--Ed
That is something in the planning stages now. You know me, I'll get around to it.
<a href=showthread.php?s=&postid=14376833#post14376833 target=_blank>Originally posted</a> by 2farNorth
Very nice Marc!
It's interesting how a couple of the PAR values went up over time near the bottom. What do you think the reason that is?
I've been running the same combo of 250w bulb/ballast for a couple years now and love it..... well except yours are screw type, and mine double ended.....
The numbers going up a bit could be due to the exact position of the sensor, or perhaps nothing is blocking the light at that moment (coral growth moved out of the way)... although I saw a couple of numbers that were up that I can't explain. In those cases, I blame the vodka.
Keep in mind that when I recorded my numbers last time as well as this time, I took was I believed was the average number from the many that flashed across the screen. I watch the numbers for about 20 seconds, noting the highs and the lows, and try to get the closest to what seemed to be the middle number (or number that appeared the most frequently) and wrote it down. Perhaps that one entry (229; bottom left of the March 2008 chart) was just an incorrect logging.
It is nice to see that the PAR only dropped ~100 over the past 11 months, but the two Reeflux bulbs are really leaning into the pinks now, which is why I'll be replacing them soon. I'm getting tempted to install some 12,000K Reeflux bulbs that I've had for some time now, but that is a lot of blue that will probably drive me crazy.
<a href=showthread.php?s=&postid=14376950#post14376950 target=_blank>Originally posted</a> by Pneumatic
I wish I could have been at the meeting!
Marc, as far as the corals are concerned is all PAR the same? I see that the 10,000K bulbs have a higher PAR than the 20,000K bulb even though they are much lower wattage. Is there any benefit to using a 20,000K bulb (to the corals, not to our eye) and if not wouldn't it make sense to use 250 watt ballasts all the way across and run all 10,000K bulbs? It seems like there would be at least some energy savings along with more PAR.
It does look like the 20,000K bulb PAR ratings are more even all the way down rather than the rapid drop off of the 10,000K bulbs. Is that the reasoning behind one over the other (other than the blue tint)?
Is PAR the same? Well, that's quite a discussion right there and it broke out during the Q&A section of my talk last night. PAR is a measurement of intensity, but these meters from Apogee are dialed in for a specific range of light - particularly sunlight. That means it is more precise around the yellows, and gets more inaccurate around the blue spectrum. When measuring electric light, it will do its best readings at 6500 to 10,000K (IIRC), but not so much at 20,000K. So would I believe every number it states under 15,000K to 20,000K bulbs like gospel? No necessarily, but it does provide us with some guidelines as to how much light is shining down. With this information, we can start sharing our results with each other and perhaps come up with some general standards for specific corals in the future.
The reason I have a 400w blue bulb in the center of two 250w white bulbs is because the blue light is weaker. If I had a 20,000K bulb that was 250w, it would be a darker shadow in the center of my reef. By using a higher wattage bulb, the goal was and is to have roughly the same amount of PAR across the entire tank. As you can see by the numbers, the 20,000K is significantly less intense, even with brand new bulbs.
We know that blue is more prone to penetrating a longer distance, based on all the video we've seen from the ocean. The brighter white / yellow (and red?) seem to drop off quickly after only 6-10 feet (guesstimate) while the blues keep things lit for a decent distance. In our tanks, we tend to use blue for aesthetics. In my own, I wanted this combination after it was explained to me, and have never regretted it. I've had this bulb color/wattage combination for over four years.
The benefit of 10,000K bulbs are growth. 20,000K bulbs make the corals look prettier, but growth is far slower because of the decrease in PAR.
I do enjoy a little energy savings in that each MH bulb only runs 6 hours a day, and those are staggered in a way that they light the tank for a total of 8.5 hours staggered. High noon (all lights on at the same time) is from 3:30pm to 7:00pm.
<a href=showthread.php?s=&postid=14377591#post14377591 target=_blank>Originally posted</a> by Padrino
Marc,
Your tanks looks beyond incredible. I think you are the perfect example of why mixed reefs are nicer than all SPS. INCREDIBLE!
Thanks.
