<a href=showthread.php?s=&postid=11073810#post11073810 target=_blank>Originally posted</a> by MJAnderson
I guess I don't understand the logic of replacing a reflector that gives a broader spread with one that gives a more focused thread and then raising it up to get...a broader spread. Is it for circulation only?
Hey MJ,
I think you can answer your own question if you read through my dribble to why it is so important to raise your lights. Secondly, if you looked at the picture of the LumenArcs that I own you will see that you need to raise those too in respect to a less than optimal situation being a five foot tank. Raising your lights will create more spread, given with any reflector.
I beleive one of the biggest reasons experienced reefkeepers tend to give the advice to newcombers in the hobby that you do not need 400 watt bulbs is out of fear that they will give the advice and the person will burn their coral. By raising your lights you are decreasing the amount of UV radiation that our bulbs give off - especially DE bulbs. What amount of UV radiation is lossed by raising your lights I will leave to the scientists. But there is some lost for sure. Another reason that advice is given against 400w bulbs is the amount of heat transfer these things give off is immense. If you have 3-5 of these things over your tank, most situations will require a chiller. Excessive heat swings can mean stress on the inhabitants which tends to turn into a chain of events where much of your livestock is dead. I would be very careful myself also when giving advice to those that desire 400 watt bulbs that their set up should consider these variables.
From the previous post again, raising your lights will mean more air circulation throughout the canopy which in turn will mean less heat build up and a happy tank. And again you will have less evaporation and RO/DI water to replace.
What do you lose out on by raising your lights? Intensity!
This is the real issue here people. Why don't most reefkeepers usign Lumenarcs raise their lights? I have an answer for you, because they will spread the light out too thin and the intensity drops to a level that "maintaining" coral becomes more difficult in all areas of the tank especially on the bottom.
These LumenBrites were designed for the reefkeeper because we want the light in our tanks. Deuce's examples are very telling as we can now see that the laser beam gets much wider as you raise them to a recommended height. The intensity is still there and that is what these reflectors are all about. Deuce if I can speak for you brother, you are probaly more shocked than any of us.
The real issue here is revealed. Most tank designs have centered around keeping lights too low to get full use out of a bulb. By driving the light down in the tank instead of out, you can raise your reflectors getting all the benefits listed above and still have plenty of light to grow SPS at all levels of the aquarium granted it is not deeper than 36".
For all of those that are afraid of the possibility that aquarium coral may suffer the same photoinhibition as coral seeded in its final resting place in the ocean where noone is photoacclimating that coral to a higher depth in the ocean, I would suggest you stick to 250w bulbs. If you are concerned about your ability to keep SPS alive because you keep bleaching them under 400w bulbs than change to 250's. For those that know how to benefit from the intensity that 400w bulbs give off, more power to you. There are examples to explain every paradox in this hobby ladies and gentleman. Mike's tank is one of them.
I have been an aquarist for 28 years and have seen every gimmick in the freshwater and saltwater hobby. A few years after I started reefkeeping , I stopped contact with pretty much everyone involved in this hobby and just kept my tanks. I did not discover RC until last year and one of the big things that brought me back ironically was all the new technology that is available to reefkeepers to help us keep our livestock healthy and thriving, not just "alive." I support anyone out there that is providing products that work for us and do what they are meant to do.
The LumenBrites just happen to be a very important step in improving the light we provide our systems as simply just one piece of the puzzle to keeping a thriving reef tank. One thing is for sure I am glad I bought a 20" canopy to allow me to set up LumenBrites in an optimal way.
Jim