METAL HALIDE BULBS

[donna2933]

Are the German Metal Halide bulbs better than some of the other brands? I just bought a used pendant with a 12K German bulb (175 watt) & I am buying another pendant which I have to purchase a bulb for. Do the 12K & 14K bulbs have the same color? I have a 75 gal. reef tank & I am adding corals and want to purchase the best bulb for the corals & live rock. What is the life of these bulbs?
Thanks!! Donna

 

[mr . salty]

I may be wrong,but it seems I read somewhere that they last three years. I hope this is true because I have two 175's that were used and I don't know how old they are. You should try to match the K value.It Depends on how deep your tank is go for the higher K bulb for tanks deeper than 24inches. STEVE

 

[clownfish]

The 14K bulbs are bluer than the 12K. I would use the 14K if I chose MH, simply because I've seen tanks with these bulbs and loved the way it looked and the incredible displays they encourage. MH is the best, no doubt about it. Unfortunately, it's also tough on the wallet and heats up tanks.

 

[donna2933]

I am using metal halide bulbs but was questioning whether the German made bulbs are better than the other brands that are on the market. I hope Mr. Salty is right about the life on the German made bulbs as I have one that has about 6 months on it and need to purchase another for another lamp. Maybe someone else will be able to give me the life of the German metal halide.
Thanks everyone. Donna

 

[reptilicus]

Hi,
MH bulbs need to be changed every year or so, after this time they lose spectrum and have a rapid decrease in intensity. The higher K the bulb, the shorter the lifespan. With Iwasaki 6500K bulbs, the life span is about 15 months, with the 14 or 20K it is much shorter, probably around 9.
IMO the best bulb is the German 10000K, I have some over my tank and love them, a truly beautiful bulb. The real advantage of the 10000K over the 14000K or 20000K is that they have a much higher PAR, and therefore are better for the corals, as well as having a longer lifespan. Especially in 175-watt, go for 10000K, as the intensity in the lamp is not that high (I have 400-watt MH's). Reefers, located in California and NJ, have a special on 10000K 175-watt bulbs at the moment, have a chat to them.
Regards,
Tom

 

[reptilicus]

Hi,
I must respectfully disagree. I have used German and US bulbs and I can say there is a large quality difference between the two. I have used both 10000K Coralife bulbs and 5500K Venture bulbs, and they are nowhere near the quality of the German 10000K bulbs I have used (both single and double ended). I will now use nothing but German 10000K lamps over my tank. They are better quality, put out more intense lighting and hold their spectrum and intensity. Not only has this been my finding but also that of many scientific studies. Also, 240-volt or 110-volt doesn't matter a bit with bulbs. I buy my German bulbs from the US, we have 240-volt you have 110, it makes no difference at all to the bulbs.
Secondly, it is imperative that you change the bulbs regularly, otherwise you will get spectral shift and loss of intensity. Spectral shift will cause in increase in nuisance algae as more yellow and red light is produced. The intensity will obviously be detrimental to the health of the corals, and both these factors will contribute to their losing colour. I change my bulbs once every year, and this is absolutely neccessary. If you get 6500K Iwasaki bulbs, you may be able to extend this to 15 months, if you have 20000K bulbs you may have to change them every 9 months, due to the lower intensity provided by the higher K bulb.
Regards,
Tom

 

[donna2933]

Thanks for the feedback about the bulbs. I can see that there are different opinions about the German made & US made bulbs, however, I have heard more positive about the German MH. I have one 12K German MH and it has a beautiful color and the corals seem to love it. Thanks for all the information. Donna