MH lighting question on a 120 gallon

[lawdog]

Hi all, I have been browsing this site for awhile and just took the plunge into the hobby today, as I ordered a custom built 120 gallon rounded edge 1/2'' acrylic tank w/ built in overflow and custom oak stand and canopy from Ostrom Mfg. in Ohio. They seemed to have the best price, service and quality for a custom built acrylic. Now that the tank is being built, my head is swimming with decisions on lighting and the such. I have researched enough to know what I want regarding a sump/refugium w/ a MR-1 skimmer and lots of LR. The lighting has me confused.

I am planning on a mixed reef tank with some soft corals and maybe more advanced items such as a clam later on. (I had a 50 gallon saltwater tank light 12 years ago; but man have things changed.) So as far as bang for the buck It seems as if MH is the way to go. I only want to have to buy the lights once, but also don't want to cut off my arm to pay for it. So I seem to be most confused on exactly what MH lights to get. I know I need retro lights to go in my canopy...but 175w v. 250w v. 400w (I think 250W for the 24'' depth of tank). If I get a 250w retro kit that say comes with 6.5K bulbs can I run 20K bulbs as I would like to run only the MH's and no other bulbs. Or do I have to get a different type base to run 20K or even 10K MH's.

Lastly to get a good MH retrofit kit to run 2 MH bulbs probably 250W that I can run a whole aray of K type bulbs on...in which direction would one point me to assist in the purchase. I have searched some of the sponsors here but don't seem to have found an answer yet. Why does reeftanklight.com sell 48'' retro kits that are 48.5'' long? I am confused as to how that would retro fit into a 4' canopy... And they do not sell 46.5' kits... Also on ebay I have seen dual 250w MH retrokits with reflectors and the whole works for like $250 new... but they only come with 5.5K bulbs... how do I know if they would run the higher K bulbs like 10 or 20K? Sorry so long but I like to ask a lot of questions before purchasing... Thanks for any help

-Craig

[Sueet]

Well, I am no expert, but I can answer a few of your ?s...

Firstly, the K (Kelvin) rating of the bulb is in regard to the color of the bulb, and you don't need a special ballast etc. to be able to run the higher K bulbs... The wattage, and style is what you have to look at..... (ie. single mogul end, double ended, etc.) A 250W ballast will run a 250W bulb regardless of the color temperature. There are SOME ballasts that will not run certain bulbs..... I can't give you a list of what will run what and how, but this link:
http://www.cnidarianreef.com/lamps.cfm

has a pretty in-depth comparison of some of the bulb/ballast combinations (all 250W)..... Most of the info there is greek to me, but I imagine if you're interested enough you'll muddle thru. (Or maybe you know greek ;))

I do know that the ones that have troubles with compatibility tend to be the cheaper ballasts/bulbs, but I would do a search here, or at reefcentral about the bulbs/ballasts you've chosen before you actually purchase just to be sure.

[saltjunkie]

thats is good advice.. get the 250 watter from ebay.. but to get higher k bulbs,, you will be looking at 70-100 bucks for each new bulb...

and... even though you said you didnt want to..
i would run atleast 2 normal output (N O) actinic lights just for your dawn dusk simulation.... it is very eye appealing and beneficial to the tank inhabitants...

[AnemicOak]

it is very eye appealing and beneficial to the tank inhabitants...

Ok, now I asked about this somewhere else & was told the actinics are asthetic only. Is there a study I can read somewhere that says they're beneficial?

Thanks


~Brian

[Sueet]

Ok, now I asked about this somewhere else & was told the actinics are asthetic only. Is there a study I can read somewhere that says they're beneficial?

Thanks


~Brian

I *believe* that they're beneficial in the softening of the transition of the light... instead of dark to super bright, you go from dark, to medium, to bright..... Not even sure that actually makes a difference, but I know that I for one hate having the sun in my eyes the minute I wake up

The big light swing is probably also a bit of a shock to fishes... the sun certainly never comes up that fast in nature.

[golfish]

Unless you like a bluer tank you might want to go with 14K bulbs. If you stick with the standard M58 ballast you'll be able to run all the SE bulbs. If it were me I'd go with either the PFO or Sunlight Supply HQI ballast. This ballast will run the 250 watt 20K Radium real nice and if you decide you want more light you can bump up to the double ended bulbs. There are some bulbs that should not be ran on this ballast but most of the bulbs over 10K will, I don't think the Sunburst bulb will.

[lawdog]

Thanks everyone... This site is great! I got it now regarding the K value of the bulb thanks Sueet for the link. Has anyone used the MH retro kits from Hallolights??? They are going for $85 a piece for the magnetic ballast or $105 a piece for the electronic ballast... Are these good MH lights? Also when you say NO lights, does that mean I can go to Home Depot and buy a mountable say double flourescent bulb with some gro lights in it?? or does NO mean something else? Does anyone have a good reason one way or another to not go with the magnetic ballasts>>?? I understand they are heavy, but other than that... any major negatives to using them. The ones on Hallolights seem like a good deal, however I know you get what you pay for and they say they are commercial grade which usually means heavy duty and well made but when all the other kits are in the $250 - $400 dollar range it makes me wonder how I can get these for like $170.

[saltjunkie]

N O.. normal output.. yes.. just the regular shop light ballasts.. or the lights in aquarium hoods.. get something like that and put actinic lights in it.. not grow lights.....

i have used those heavy duty magnetic ballasts.. they worked fine for me.. i think they draw more electricity.... could be wrong though

[golfish]

their not mounted in a heat sink, didn't look but probably no quick disconnects, use more juice. It is what it is and you do get what you pay for.