Unhappy Corals at High Noon: New Light Acclimation 12/19/04
Hi Guys, Thanks for the great site and advice :)  
<Howdy, and thanks :)>
In my tank I have two hammer corals (used to be one big one that got too big), an Alveopora, star polyps, and I recently just added a show rock with about 4 different kinds of zoanthids and various polyps.  At the same time I added that rock, I doubled might power compact lighting from 95 to 190 watts. This was about two weeks ago.
<Hmmm... no mention of an acclimation period and a clear indication in light of the mail title where this is going <G>...>
Since that time, every day my lights come on at 10am and all the corals expand and look very healthy.  Then at about 12 everything starts to close up and look sickly until 3pm.  At this point everything starts to expand again, but not to a large extent.
Is it possible that the rock with all the polyps on it has incompatible polyps that are engaging in chemical warfare?  
<always present, yes... but to the extent that it causes these symptoms already... not sure.>
It's obvious that all of the polyps were glued on,
<Ughhh...>
and thus I'm suspicious because they did not grow together naturally.  
<if so, they will not stay together, rest assured. They will separate or kill each other sooner rather than later>
Or could it be the lighting change is having some effect in the middle of the day for a few hours?
<is possible, even likely. Such dramatic changes in lighting require a much more gentle acclimation. Keep the same photoperiod, but add some layers of plastic fly screen for a couple weeks (after new lamp replacements too). Remove a sheet every few days and soon the acclimation is done. Anthony>

UV Hazard, Real for Cnidarians? 7/13/03
Seems as though the consensus among you all is that MH lighting requires some sort of UV filter.
<not always... depends on the coral you keep. Some need UV to keep their natural color... others change or suffer due to excess exposure. Health and vigor issues too. I lean towards allowing UV into the tank... but not into the room (protect your eyes via a closed canopy)>
However, I have read elsewhere that MH lighting does not produce nearly as much UV-A, B or C as the sun and in that context, shallow living reef creatures can handle it.
<varies by lamp>
I've got 3 X 175W over a 175 gallon, 24" deep tank (not sure of the brand, box was unmarked as to manufacturer but they are 10,000K with mogul base).
<do inquire about bulb brand.. some are just terrible, others like Ushio/Aqualines and Iwasakis are very good>
Is this a matter of debate or would you say there is no question regarding UV hazard? Regards.
<depends entirely on the species being kept and from where upon the reef it was collected. Most corals are adaptable over time at any rate. Best regards, Anthony>

Metal Halides for SPS - 3/22/04
Dear Crew:
Thanks again for the great website. <Thanks for being part of it all>  I have read your FAQ's and articles about MH lighting with great interest. <Glad to hear. Helped me too> Here is my situation:  I currently have a 55gal (48x13x20) tank w/130W PC's. <OK> I am going to get a bigger tank this year, probably a 125 (72x18x22).  I would like to keep some clams & SPS, so I am looking at MH. <I think a good choice> Also, I believe HQI DE bulbs and fixtures will give me the best for my money. <Many thoughts here but I use the HQI ballasts and DE bulbs> Now, according to Bob's response in one case, with "some" clams and SPS, I should be able to go with 175W lamps.  However, I have only seen HQI in 150W and 250W flavors. <Correct. Go with the 250>  The difference in price is about $20, so it would seem wise to get the 250W. <Exactly> However, I do not wish to have the extra light if I do not need it. <Yes you do>  I could probably go with 2-150W lamps for the 55 now, and get an extra one when I get the 150gal. <That will work>  I thought about 2-150's and then the one 250 later, but I am not sure how I would feel about the spotlight effect (I assume there will be one). <Not really. At the Monterey Bay Aquarium we have 400s and 1000s and notice very little difference>  Before I forget; I know some of you don't like to say, but which would you pick of the 2 choices
I have for either 150W or 250W:
1) PFO HQI ballast, 10K DE HQI Bulb (brand not specified - email pending to vendor) and PFO HQI Mini Pendant <This is what I use and love it!!>*OR*  
2) IceCap Electronic HQI Ballast, Ushio or Aqualine (AB) 10K DE HQI Bulb <Both great bulbs but I use the Aqualine HQI bulb> and Sunlight Supply Reef Optix III Plus Horizontal Reflector. <Good reflector but I am really happy with my PFO. We use PFO on occasion at the Aquarium as well. Quality and Value in my experience. Happy reefing! ~Paul>
About choice #2, I have seen some vendors insist that the Sunlight Supply Reflector must run with Blue Wave Ballast.  If this is true, what makes the IceCap okay in this case?  Is there some sort of overdriving or trickery going on here?  Hey, thanks a million, Rich.

LIGHTING???
I wanted to know your opinion on Ice Cap VHO lighting?
<A nice product and lighting format.>
I am setting up a 55 gallon reef tank. I also wanted to know why do they sell lights that are 46.5 and lights that are 48 in length?
<48" is pretty standard, but sometimes will not fit inside of a canopy for a 48" tank.>
Which ones do I get?
<The larger ones if they will fit.>
It seems that the 46.5 would be fine and so would the 48's? Also, if I use this type of lighting what is the minimum and the maximum wattage I can use?
<Depends on what you want to keep.>
I would like to fill my tank with mushrooms, polyps, soft and hard corals!
<Hard corals is a rather large and diverse group. If you stick with what you mentioned and LPS hard corals, two 110 watt VHO's should be fine.>
I want enough light to start out with to get what ever I would like in the future.
<Impossible>
Is there such thing as too much light?
<Yes>
One more? Again with the VHO there are three kinds of lights:
URI Actinic white
URI Aquasun
URI Actinic 03
What is the difference and what would you recommend for my 55 gallon reef tank?
<The Aquasun is a full spectrum lamp, actinic 03 is a blue lamp, and white actinic is a combination of the two. One Aquasun and one Actinic 03 should be good.>
Any advice would be greatly appreciated!
Thanks, Nattalie
<You are welcome. -Steven Pro>

Lighting upgrade question
Hello Gentleman,
<cheers, mate>
My 75 gallon reef tank currently has two lighting hoods on it.
1) JBJ Formosa Deluxe 4x65 PC (2 7100 + 2 10k).
2) A plain old 40w NO fluorescent with a Coralife 6700k bulb.
I want to replace the 40w NO with a Custom Sea Life 2x65 PC SmartLite system.
The 4x65 Formosa will remain, giving me a total of 390w of PC lighting.
I have four corals in the tank: One piece if live rock covered in metallic green mushrooms, one short tentacled tongue (plate) coral, two brains -- one red and one greenish / purple.
<all low to med light animals that require regular feedings (3-5 times weekly... or tiny bits daily for optimal growth>
The tongue and brains are on the substrate, 
<excellent and as they should be>
the mushrooms are about halfway up the water column along the back of the tank.
<OK>
Should I be concerned with any light acclimation issues, or is this proposed upgrade 'safe' as is?
<reasonably safe indeed... fluorescent lamps just don't have that much punch (good and bad) and the upgrade here is not severe>
Thanks in advance. Sincerely, Mark Schwartz<do look here for further "illumination" of the subject (sheesh that was cheesy :p) http://www.wetwebmedia.com/acclimcoralslight.htm 
and here: http://www.wetwebmedia.com/marlgtganthony.htm
best regards, Anthony>