175W MH 14K K bulb

[dwdenny]

what do yall think about this setup. Single 175w MH 14K K bulb. I was thinking 14K K to keep from using any other type of lighting in addition to the MH. This will be going on a mushroom, ricodrea and rhodactis tank. The only problem that I will run into is the center brace however I think that if I mount the light a little higher say 8" off the surface then the light would bend around the brace and not have as much of a shadow.

Thanks
Doug

[GaryP]

Just remember the higher you mount the bulb, the lower the intensity you will be delivering to the tank. Intensity decreases with the square of the distance. So, that means doubling the distance, decreases intensity by 1/4.

[dwdenny]

was kind of counting on that as to keep mushrooms on the bottom and not have to much light on them. Do you think that if I mount the lights closer that they(mushrooms) would be ok? Tank depth would only be about 18" or so. And that brace is a killer don't want to much of a shadow may have to get a small PC light for the front to keep that shadow out will find out when it gets built.

[GaryP]

If you aren't intending to do any SPS or clams (maxima or crocea) I don't know that I would even use a MH. Maybe PC's or T5s?

[dwdenny]

You are right. Maybe an overkill on this tank. Just thinking out loud and wanted some opinions thanks. I was thinking T5 lighting but how much to use is a hard thing to define. I was thinking with T5 4X39W would work however I could get a single 175w MH for half the cost of T5's. That is why I was thinking of going with MH.

[GaryP]

T5s have other advantages that will save money over the long run such as electricity and replacement cost.

[dwdenny]

yeah I was looking at that as well. What is the average life of the T5 any one know. I thought I saw that there was people using them for over 18 months. I find that hard to believe that the spectrum has not decreased over this time. I was thinking that they could possibly last up to a year maybe just not sure. Do you think that 4X39W T5's would be plenty of light for a 46 with mushrooms and rics.

[dwdenny]

I did some comparisons and hte difference with bulb cost and replacement are not the different about 38 dollars and electricity is only about 40 dollars difference over a years time. I can imagine that the intensity will not last a full year but I am not sure as these seem to be a new technology and seems no one is testing them to find out.

[GaryP]

I am running 4 X 110 watt VHO's in my 75 gal. softy/LPS tank. I'm not sure what the comparison between VHO and T5s are.

[dwdenny]

No one has answered that question yet to me either. I have asked that question in different forums but no one tries to answer it. I was originally going to go with 3X75W VHO which is 225total watts with one 175w and 2 36w PC Actinics that is only 247 not much difference on the electricity bill. However the bulb replacement is a little cheaper but replacing them twice a year or so comes out to darn near the same. So I though why the heck not just go with MH and get the nice shimmering effect for the little extra cash.

[Polkster13]

The amount of heat that the MH produce will also need to be taken into account. The PC and T-5 don't produce anywhere near the same amount of heat. I have MH, VHO, PC, T-5 and NO bulbs on a variety of tanks and systems. The MH produce quite a bit of heat (I have them in a very small room and the room temp stays in the low 80's) just to get that shimmering effect. You will need to run the A/C a little cooler or put in a chiller so that will need to be figured into the cost equation as well.

[dwdenny]

well we do run the A/C at 75 but I think it is off because the room runs in the 72-74 range during the day and about the same during the night Plus I will have two fans in the hood as well as the back will be completely open. This will be in the living room so the temp will be pretty stable and cool with a cieling fan. Like I said above this is not set in stone but for $280 I can get a CoralVue 175w MH with 2X24W T5 actinics or I can get a 4X39w T5 setup for $329 not a big price difference but big enough. Nothing set i stone I can always change my mind right before I purchase the lights. I relly do appreciate you alls help in making up my mind.

[mharris7]

IMO metal halides are more expensive on electricity not because of the wattage but because of the ambient heat they put into the room, thus causing the AC to run longer to compensate. It's a big deal in the summer. I love the look though.

[witecap4u]

What size of tank is this going on?

I would get a nice 14-20K bulb and not worry about actinics. Even though it is overkill for what you want to keep right now, it will allow you to change your mind and not have to worry about swapping your lights in the future. Look at the 150W HQI's as well as the 175W SE setups. With just the singe bulb, you'll only need to spend <$75 on bulb replacement a year.

As far as heat goes, we are talking 1x175W bulb, I dont think the heat will be that intense that he will need a chiller, unless the tank is like 20 gal, but I doubt it is since it has a center brace. I ran a 400W over a 44gal corner tank with a single fan in the canopy and didnt have heat issues, just alot of evap. and our electric bill hardly changed at all, or at least not enough to care about.

Just my thoughts
cs

[smelleybrad]

Maybe this will help

http://www.c-sea.org/members/brad/articles/light/#metalvsflour

[Ram_Puppy]

I have a 14K hamilton that has about 200 hours on it, The ballast went bad so I ditched the fixture, but I am pretty sure the bulb will still fire if you want to give it a try. very pretty bulb.