Metal Halide Lights

[Pat]

Hello everyone,
I have a 29 gallon tank and I'm buying metal halide lights. I am going to go with a retrofit kit because it is the cheapest. I'm thinking about buying a 250W Retrofit Kit with an ARO electronic ballast from hellolights.com. I am looking at an XM 15,000K bulb. It will be supplemented with a 55W power compact that I already have. Does this sound good? Sorry for the basic questions I just don't want to buy something and then regret it. Is there any particular bulb color that gets better growth? I read that 10,000K is the best for growth. Thanks for the advice.

-Pat

 

[nunofs]

You may want to check the recently published PAR results of the XM 15000K bulb, many people were disappointed with the amount of light it puts out.

Usually, the warmer the light temperature (ie, the closer to sunlight), the better growth you get, but the tank may look yellowish and there won't be much fluorescence... I think a "true" 10000K with actinic supplementation is great for growth... go higher if you like a more blue look (I'm currently using the Phoenix 14000K and I like the crisp white/bluish look; and great PAR, too).

Nuno

 

[Piscevore]

AB10,000k = (around 12-13000k)

 

[NateHanson]

At the risk of opening another can of worms, I think you might have a heat problem with a 250w MH over a 29g tank. Do you have a sump? Air conditioning? Enclosed canopy or hanging lights planned?

 

[ceige]

my 30 has a 175 mh (10K) and (2) 75 vho for actinic and heat is a big problem for me....

 

[Piscevore]

It -would- be an issue. No contest.

 

[this is me]

I ran a 250w HQI on my 29gal before I switched to my current tank. Let me tell you, be ready to handle the heat!! If you dont have a fan blowing across the tank and your room is AC, your tank is toast! even if you have a sump.
There's another member here(Peter-Ultimatenoob) that is running a 29gal with 250wHQI. He has a huge fan blowing across the tank and the room is AC. He also has a sump.
Are you planning to use 250 SE? it's not as hot as DE but it still can heat up the 29gal pretty quickly.
You said you're getting a retro kit, that mean you must have sometime of a canopy? If you build your own, make sure to drill some hole to fit the fan on the sides.
If you're gonna supplement actinic, go with a lower K bulb. perhap a 13k or a 10k.

 

[TheUltimateNoob]

hey pat,

i also have a 29g tank with a 250w DE metal halide over it. heat can definitely be a huge problem unless things are done to control it. first of all, i don't use a canopy but use a pendant hanging from the ceiling. the light hangs over 12" from the top of the tank. i also have a regular house fan blowing air across the top of the tank because it gets extremely hot directly under the light. lastly, my house is always air conditioned. even with all these things, my tank can sometimes get up to 81.5 degrees. so definitely take the proper precautions. hope this helps.

 

[Pat]

First of all thanks for the advice. I think I am going to get an Aqualine AB 10,000K. Its a little more expensive but all I have heard is good reviews. I know heat is going to be a problem. I built my own canopy and it is 10 inches tall and the back is open. I am going to have two fans blowing. Would it be a better descion to just spend 100 more dollars and get a pendant? The problem for me with pendants is I have a wrasse in the tank so I must have the top covered. Thanks again.

Pat

 

[this is me]

dont spend the extra 100 on a pendent. A pendent require you to hang it from a ceiling and it an eye sore when you look at your tank because of the glare.
spend the extra 100 on a sump or an ac if you dont have it already.

 

[NateHanson]

If you like your wrasse, stick with the canopy. If you haven't already, get a sheet of "Eggcrate" (white plastic grid used for a diffuser under flourescent fixtures) at home depot and cut it to exactly fit the back cut-out of your canopy. That'll allow lots of airflow, but be a nice backboard for when your wrasse takes a jump-shot.

Nate

 

[Pat]

this is me- I have a 10 gallon sump (about half full so thats more like 5 gallons) and the room has a window air conditioner. I only run the ac on really hot days though because it uses a ton of electricity.

NateHanson- I've seen that light diffuser before. I didn't buy some because it confuses me. If it diffuses light then isn't it going to stop the light from getting to my coral? I guess this is just a stupid question because I've seen people use it on their tanks before with success.

Also just a general question. I don't need UV glass if it is a single ended bulb, right? That is just for DE?

Pat

 

[NateHanson]

You don't need a glass shield for SE bulbs.

I do think the eggcrate will cut down on light to the tank, but I'm actually suggesting a section of eggcrate to cover the open back of the canopy. To keep the wrasse from jumping over the back edge of the tank.

You'll probably find that with the new MH lighting you'll be running your AC much more often, but that's ok because the MH light is awesome for your tank, and MassElectric appreciates your business.

Nate

 

[Pat]

Oh now I understand what your saying about the eggcrate. So I will have nothing between the light and the water. Sounds pretty good.

On a different subject I'm thinking about making a closed loop perimeter manifold to create ideal flow. Is this overkill for a relatively small tank? I am planning on 4 outlets.

Pat

 

[nunofs]

eggcrate to cover the open back of the canopy. To keep the wrasse from jumping over the back edge of the tank.

Depending on the size of the fish (and their determination to commit suicide) they may be able to go through the eggcrate, I've had this happen with a firefish (which I rescued)... what I've done is use two panels of eggcrate, one behind the other, so that the grid is offset between them... this way you effectively make the holes 1/4 the size of the original eggcrate, which seems pretty safe even for a narrow fish like a wrasse or a firefish.

Nuno