[tommtn]

Hi, I am just getting back into salt water and am looking to set up a 55 gallon reef (36 long due to space contstraints). I don't know exactly what types of corals etc I will keep but want to have flexibility. I have not yet bought anything but have been readling a lot of posts and a few books over the last several months, and have made several rather unhelpful trips to a couple of LFS. Needless to say, this whole lighting thing is a little confusing!

First, I have really enjoyed reading this discussion. Now, for my own issues:

I live in San Francisco so electricity is expensive . Another issue is that my wife wants the tank to be as quiet possible. I would therefore like to to have totally enclosed hood-- I don't know how loud fans are, but I would like to avoid them if possible if they are noisy. (it is generally cool here so I did not need fan with my last tank (29 gallon FO tank with 50/50 Corallife bulbs). I plan on getting an acrylic tank, pre-drilled, and have a sump. I will use a DSB and live rock with a skimmer.

For lights, I initially though PC would be best (LFS led me that way) plus I like the idea of using as little energy as possible to get the most light. On the other hand, I have heard that MH are actually quite efficient with respect to the amount of light they generate and there appears to be a relatively strong concensus that MH are better than PC. I also am not excited about buyng something now (like PCs) and then going out and redoing the whole thing in two years. I did that with my last tank and would like to minimize that as much as possible.

I have read some posts that suggest MH are actually not more expensive than PCs over time due to the replacement costs of the PC bulbs. I don't know if that takes electricity costs into account, however. ALso, I don't know if it is reasonable to assume that the cost of PC bulbs will come down quickly because they are a new technology. I know compact flourcent bulbs for everyday use are a lot cheaper now than a few years ago.

I would also consider a combo sysem with VHO/PC combined with a MH if that makes the most sense. Anyway, thanks in advance for any advice.

[dattack]

If initial startup cost is not a concern and you stated you wanted flexibility with your corals and have a lower electricity bill, you should definitely look into the HQI for your lighting needs. It provides more than enough lighting for your corals/clams and yet will in the long run save you money on the electricity bill.
There are a few fans that run fairly quiet (I don't have a quiet one unfortunately) and I think you will need a fan if your hood is enclosed for a reef tank.

[Ltspd]

I would suggest (2) 175w 10kk standard mh and (2)36" NO URI super actinic bulbs.


The use of HQi's require a shield between the bulbs and the water and they can not have air blowing across them. Since this will be a enclosed hood (not suspended) heat will be of concern. If you would suspend it I would go with HQI's. But if not then you can add a couple of quiet radio shack fans to cool the hood.


You really should think about suspending the light hood, allowing a air gap between the tank and the hood itself. It will allow you to use HQI's which IMO is a very good bulb, has plenty of PAR (see Sanjays 2002 report) and is energy efficinet for a mh.

[tommtn]

Thanks for the feedback. One of the reasons I need an enclosed hood is that I have two kids (1 and 4) and I want to avoid silly putty and other not-so-silly stuff ending up the tank.

Can you use HQI bulbs in an enclosed hood with a fan if the fan is below the UV glass?

Also, do you think one 250 would be enough for a 55 gallon (perhaps with two NO actinic) since it is only 36 inches long? WOuld I be better off with two 175 bulbs and no NOs?). Thanks. Sorry if these questions are too basic.

[Ltspd]

One reason I am suggesting (2) 175w standards is becasue in a enclosed hood you wont be able to go as high unless you build the hood taller. A mh bulb will light a 2ft sqr area if placed 12-18 above the tank. So a 36" long tank will be dim on the ends.

You might be able to cool under the HQI's glass but here again you are raising the height of the hood. They also recommend that they be 12" approx above the water surface.

Now, depending on what you wanted to keep you could get away with (4) 48" vho's using a nice system such as this.
http://hellolights.com/4lampvhokit.html

Problem with a system like above is that you can not have a "blue" period of dawn/dusk which is appealing to some people including myself. But, this is a energy efficinet electronic ballast and you can run (4)VHO's. It is also pre-wired and comes with endcaps, all you will need is bulbs.

[tommtn]

Thanks.

Do you know the power consumption of four VHOs compared to the MH or PCs? Can I just look at the wattage of the lamps and add them up or do I also need to know the power consumption of the ballasts? Does the length make a diffence?

I have read an article on "Do ballasts make a difference" that provides some good info on using different ballasts with various MH lights but it does not discuss other types of lighting.

[Ltspd]

Power consumption is based off of the ballat not the wattage used for the lights.

Yes, Length makes a diffrence.

[tommtn]

Thanks for the info. I am still not sure which way to go. I am leaning toward 4x96 watt PC for initial cost and ongoing cost and the ability to avoid a chiller. I know on some BBs there is an extremely strong aversion to PC but they sound pretty good from a power consumption and total light output perspective. Also, it sounds like there are now true actninic PCs out there. Is this really dumb or does it sound OK. I have a lot of other cashneeds for the new tank (like everything!).

On an unrelated question, is there any info on the UV exposure for people outside the tank. My kids would mostly be looking up into the tank. Is that something to think about. I read an article which suggested, based on tests, that the unshielded MH lights throw a lot of UV, even the ones that are supposedly shielded.