14k---20k

I just bought 2 250W Mh pendents and will need to switch out the bulbs (which are 10K) due to a lack of actinics. Can I get a vote on 14K versus 20K for the replacements it will be some time before I get any additional supplimental light for the tank.

It is wierd and depending on the manufacturer you are going with it can even be more confusing. How much blue do you want and what do you plan on growing?

Picture comparison of some of the major bulbs
Reef Central Online Community - 250 watt SE MH lamps compared

Par spectrum comparison graphs can be found at this link
Sanjay's Reef Lighting Info Pages

I don know from local hobbiest/friends you want to go with the XM 20ks over their 15k always... I can't speak for the other manufacturers, as I personally use DE Bulbs... hopefully someone will jump in and help you a bit more.

Brandon

Also comments on these?

eBay: 250 W Metal Halide 65k,10k,14k, 20k bulb Aquarium Light (item 220016217839 end time Aug-20-06 13:55:37 PDT)

Im in favor of the 14K, however, some like the 20K. Check out the bulbs spectrum spikes as not all bulbs are identical.

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Retracted post. follow bks links. you will get some very good information there. also be careful on the bulb you pick as some spike at different spectrums although the rating is the same.

So let me see if I got this straight...When screwing in a mh bulb it can chage color depending on where you stop screwing it in?? If that is the case that's pretty cool because if you weren't happy with the color just rotate the bulb.?.? I am new to mh so I am just trying to understand, I had never heard of that before.

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Not exactly, i sent salt newbie a pm further explaining what i was trying to share. so to set the record straigt turning the bulb does not change the visual spectrum but the position of the inerds does and these can be adjusted by turning the bulb. hope this clears it up.

I just ordered 2 Hamilton 14Ks. After looking around at all the different options the Hamiltons looked the best to me. So we will see how they work. I got a great price on them 49.99 each and shipping was about 10 bucks.