MH differences

[SaltyTemple]

Okay - so I'm looking for a replacement 250W bulb for my tank.

My question is this - what are the differences between the bulbs? I see prices ranging from 60-160 on 250w 10k and 20k bulbs. Which is appropriate for my 125? I have a clam and sps' under this light (even some mushrooms,) but my main concern is for clam.

Also, how can you tell what "color" they'll be? I had a white bulb and a blue bulb, QUITE different! What's "better?"

Any insight or good links which would educate me would be appreciated.

 

[Elmo18]

Hi Shauna!

Here is a very informative link giving some bulb information and what they look like, with and without actinic supplementation. Some parts you can skim, but there are definitely tables there that you may want to look at.

I am not sure if you have visited Sanjay's site on lighting, but that is a great resource as well.

The one I'm talking about is by Joe B, in New York, here is the link:

http://www.cnidarianreef.com/lamps.cfm

For growth, the higher the PAR rating, ideally is better. However, more growth may mean sacrificing 'color'. I am talking very very general here. So the 'look' is just aesthetic, and depends on you. However, in my opinion, the type of bulb you choose also depends on tank height, water clarity, ballast used...etc.

My experience with bulbs is a short one, since I started with Iwasakis about 4-5 years ago and found they were too yellow for me. Then switched to XM 20ks, which I found too blue. Then switched to XM 10k's 250W SE bulb, which I am currently running. Very nice crisp white, and im running without supplemental actinics. Now i have tried the XM 15ks...and in my opinion, growth is much slower with the XM15ks, definitely much lower PAR values than the 10k XM.

Again...my bulbs of choice would have to be XM 10k SE, but would be careful when adjusting corals as it does have high par readings, if you are switching from a 20k bulb. If you would like to try it out, I have a used 10k XM 250 watt bulb that is about 6 months old. The one over my tank is 10months old, and still rather 'white'.

Best,
Ilham

 

[SaltyTemple]

Alright, so I understand that 10's are less blue than the 20's. What would you all suggest? the 14's?

 

[NaH2O]

Here's the link to Sanjay's site that Elmo made reference to: Sanjay's Reef Lighting Info Pages. Color of the bulb is really an opinion. Currently (until I see a bulb that I like better), I prefer a 10K bulb over the 14s or 20s I've seen, as I feel they are too blue. Some folks prefer the 14s because they like the way it looks.

 

[Elmo18]

Here's the link to Sanjay's site that Elmo made reference to: Sanjay's Reef Lighting Info Pages. Color of the bulb is really an opinion. Currently (until I see a bulb that I like better), I prefer a 10K bulb over the 14s or 20s I've seen, as I feel they are too blue. Some folks prefer the 14s because they like the way it looks.

Thanks Nikki I knew i had it bookmarked somewhere...ah yes on your computer... :razz:

- Ilham

 

[SaltyTemple]

thanks a ton guys!

 

[SaltyTemple]

I'm having a hard time deciding on the next bulbs. My experience is limited. Thus far, I have had a 10k XM and a 20K XM, the 10 is too yellow and the 20 is too blue (just for my taste)

I like from Elmo's link the Hamilton 14k and CoralVue 20k - can anyone give me some practical advice on this?

 

[WaterDogs]

Most clam people go with 10KK bulbs.

 

[NaH2O]

Shauna - have you tried or seen the 10Ks with supplemental actinics? If you think they are still too yellow, then you'll probably enjoy the 14K bulbs. Don't forget to acclimate your corals to the new lighting.