PC light replacement      9/5/12
Dear WWM,
  It is that time of year again where I get to change out my lights. I have been browsing on Marine Depot and found the 65 watt light, but it comes in several variations I am unfamiliar with. I have been using 10k lights. I need 8 total.  They have a 12k and 6700, should I even consider these for the tanks? I keep LPS corals in my 55 reef tanks. Should I look at maybe 4 10k and 4 12k? Would there be any benefit to something like this? Thanks.
Bryce
<For functions' sake I'd go w/ mostly the 6,700 K lamps... for looks you might mix in a few of the 10K. BobF>

Actinic PCs'¦Do I Need Them? -- 03/30/10
Hello,
<<Hiya John>>
I have the Coralife retro fit kit over my 125 gallon tank. It has 3 150 watt HQI double ended metal halides and 4 96 watt PC actinic. I just replaced the halides with Ushio 10ks.
<<And a nice upgrade over the stock bulbs that came with the unit>>
I know the PCs are old, but do not know how old because I got it used. I think they are 1 to 2 years old.
<<Mmm, okay'¦and as PCs go, these are indeed 'old'>>
I thought I read someone on WetWebMedia saying that the PC actinic lights would not do much in a setup like mine.
<<That depends on the context of the statement I suppose. As far as useful light energy goes, no, the PCs are not needed/do not much as the metal halides supply the required intense light energy (even in the blue/actinic range) for your photosynthetic organisms'¦as far as aesthetics go, if this is your thing then yes, the PCs can add some extra 'glow' to the setup>>
Not really sure if I understood correctly. Should I not bother replacing the PC actinic lights at all or maybe replace them with 10k or higher?
<<Up to you, really'¦ If you like the look of the tank 'without' the Actinic PCs then replace these with a 10K bulb>>
If I should get actinic lights, what kind?
<<I don't feel it matters'¦ Get what suits your eye and your budget>>
I see they have 460nm, 420nm, and dual 420nm/460nm. At least give me the pros and cons or a suggestion.
<<I suggest you not sweat it and just 'pick one' based on the way it looks/what appeals to you>>
I don't really know the difference. I have mostly LPSs in my tank a brain, elegance, bubble, trumpet, candy cane, softies, and a few SPS frags. On a sort of unrelated note when my halide bulbs went bad the lights started tripping my CGFI, but that stopped after I replaced the bulbs. Is that normal or possible?
<<Normal'¦don't know'¦but have not ever experienced this. Possible'¦I reckon'¦arcing of the bulb/voltage fluctuations may well have tripped the ground fault, especially if it is old (GFCIs also go bad/require periodic replacement)>>
I got the lights used about 6 months ago, so I think they were really old and really bad.
<<Quite possibly so>>
Thanks,
John
<<Happy to share'¦ EricR>>

Re: Actinic PCs'¦Do I Need Them? -- 03/30/10
Hello again,
<<Hey John>>
Yes, I was wondering if the PC actinics had any added photosynthetic benefit or if they were purely aesthetics.
<<In a setup such as yours, this last is pretty much the case>>
If they are just for looks then I am fine with the way they look now and would not bother replacing them.
<<Indeed'¦I let my T5 Actinics burn till they 'won't burn no more.' These are merely used for day/night transitions and for the small amount of phosphorescence they produce. The real 'punch' of my lighting system, like yours, comes from 10K metal halides>>
If replacing them would help my corals then I would spend the money to get new ones. So the PCs do not provide any light energy at all or is so little that it is not worth it?
<<The Actinic PCs do produce light energy, it is just that this short-wave light is supplied in plenty by the metal halides, and alone is not nearly as important as supplying good full-spectrum lighting to your tank (i.e. -- your 10K metal halides)>>
I thought I had about 800 watts of light before, but if the PCs are useless PAR wise then I am really down to 450 watts right?
<<Indeed'¦if counting watts and measuring/determining lighting requirements in this way (which is by no means 'cut and dry' as the type of light source, reflectors, tank dimensions, photosynthetic requirements of the organisms kept, et al, must also be considered) then I would not include the PCs>>
That is what I read before then, but I just found it shocking because some people get PCs only for their tank.
<<They do, yes'¦but they also don't generally use ALL Actinic bulbs and they learn to understand and work within the limitations of this type lighting>>
To clarify, PC type of light just isn't intense enough to do much PAR wise or is it actinics don't do much PAR wise and are for looks?
<<More of the latter>>
I could get 20k PCs if they would help my corals, but again if the PCs are not intense enough to matter for PAR then I will just stick with the old actinics until they burn out because they look fine as far as aesthetics go.
<<With the 10K metal halide lighting you have, I would leave the PCs as they are>>
Thanks,
John
<<Always welcome'¦ EricR>>

Filter Question... Tidepool/Marineland Wet-Dry wheels, skimmer sel., CF lamp sel.  3/13/10
I have a 150 gallon aquarium with two corner overflows. I have 2- Tidepool 2 filter systems. Can you give my some advice on media to put in these?
Should I be using the bio-wheels?
<If you have live rock in your system, I would not use the bio-wheels.
Because of their high efficiency at denitrification, it is likely that the nitrate levels will increase in your system.><<RMF doubts this... I'd leave these wheels on/working... can be removed for experiment...>>
Can the heaters be housed in here or better in the main tank?
<Much better to place them in this filter/sump.>
Could you recommend a good skimmer?
<I like the Vertex and AquaC line up, a lot of bang for the buck.>
Lastly, would 4, 50/50 compact bulbs be as good as 2 daylight, 2 actinic?
<Should be, 50/50 is generally referred to as 10K daylight, 460nm actinic.>
Thanks,
<You're welcome. James (Salty Dog)>
Dawn

Specifications on Power Compact Lamps Power Compact Lighting Questions/Reef Lighting 1/12/09 Good morning! <Hello Jim> I'm trying to understand the long term lighting needs for my 2 year old, 90 gallon reek tank. I've searched this site and others. I've recently re-read Mr. Fenner's article entitled "Marine Lighting: Quality, Quantity & Duration." I believe I now understand the methodology required to figure out what I want for my system. I'm having a hard time finding complete information on individual Power Compact lamp bulbs however. Most list degrees Kelvin, and wattage (which I assume to be power consumption, not output.) I'd like to compare CRI <Note that the CRI by itself does not indicate what the color temperature of the reference light source is. CRI is the ability of the lamp to display accurate colors.> and Lumens as well, but haven't found this information on most manufacture's sites. I currently have 4x65w, 21" "50/50" Coralife lamps. I haven't been able to figure out what I really have now. <What you have now are lamps with a mix of 6500K and actinic blue which is generally 460nm.> Are you aware of a resource that has made a comparison of various brands of these lamps? I'd sure appreciate a referral. <Am not, but you should be able to get this info by emailing the company directly. Reading here may help you better understand your reef lighting needs. http://www.wetwebmedia.com/marlgtganthony.htm James (Salty Dog)> Regards, Jim Lambeth Seattle

Changing PC bulbs 8/27/08 Dear crew -- <Hello> We have a 55-gal FWLR salt-water tank. We do have a couple of corals that came with our live rock (the SPS seems to have survived, mostly). <Great!> We have 2x 65W Actinic + 2x 65W 10000k Daylight fluorescent lights on the tank. It's been six months since the last light change, so we are swapping lights. We realized that it would be better to swap two every three months instead of all four every six. <Six months is more than fine, still very conservative.> So we're swapping one actinic and one daylight today. Ok, all of that was to ask this simple question. Which is more important to an SPS coral, the actinic or the daylight? <The daylight, actinic is aesthetic, the daylight actually provides all the blue the corals actually need.> Since we're only going to be replacing one of them above the SPS, which one should we replace above the SPS, and which one should we replace on the other side? <Either or, you are still well within the need to change these bulbs; mine are done every ten months or so (still conservative in my estimation).> Thanks Dave and Laura <Welcome, Scott V.>

Odyssea Lights 7/3/08 Hello! <Whit> I was wondering if Odyssea power compact bulbs are any good. <Sure, they are fine.> I know in the past they have been less than reputable, but am wondering if that had changed. <I still read things about the fixtures, but never the bulbs. I have never seen the firsthand failure of either from this company.> Also, in a 46 bow with Frogspawn, Zoos, Kenya Trees, Mushrooms, and Button Polyps, what combination of lights would you recommend? I can fit three bulbs, any thoughts (how many 50/50's, etc). <Perhaps one 50/50 up to one full actinic with the balance daylight. This is covered to death on WWM, eighteen pages re marine lighting to date, start here: http://www.wetwebmedia.com/marine/setup/lighting/faqs1.htm > Thanks again for your time! Whit <Welcome, have fun, Scott V.>

Too Blue? Hey guys, <Scott F. your guy today!> Got a lighting question. I have a 65 gallon tank with LPS and soft corals. I have 3 96 watt pc's, 1-actinic, 1-10000k, and I was wondering what the third should be... 6700k? 7100k?20000k? Thanks, Justin Barstows <Well, Justin...it all depends on the specific species you intend to keep, as well as your aesthetic preferences! Even amongst the various LPS and soft corals we keep, light requirements (both spectrum and intensity) are highly variable. I, personally favor another actinic-but a lot of people find that "too blue", regardless of what the corals like! If that's your feeling, too, then I'd go with another 10,000K...Either should work fine. Your call here! Good luck! Regards, Scott F.>