20k vs 10k

[kinerson]

If both a 20000k metal halide lamp and a 10000k metal halide lamp have the same par rating, would the 20000k be a better lamp choice since it produces better color? Would the growth rates generated by both lamps be somewhat equal?

Thanks,
Greg

 

[musty baby]

Probably. You won't find such a pair in the same wattage though.

 

[a4twenty]

equal par equal growth

 

[kinerson]

The XM 175 watt MH 20k has a par rating of 51 on my ballast which is higher then my current 14k lamps that are being supplemented with vho actinics. I only running two halides presently and I'm considering running all three and doing away with the vho actinics. Most of my corals are LPS and zoo's that seem to perfer the bluer light (and not nesseceraly bright light). I'd like to switch to 3 20k MH w/out actinics to increase "shimmer" and save a little in electricity as long as I don't seriously hinder the health/growth of my corals.

Do you think this will work ok?

Thanks,
Greg

 

["Umm fish?"]

What's the goal of your tank? Either can give you healthy corals. If you want to max out the growth then go for the higher PAR. If you like the color of the bluer light and don't need to max out the growth, go for the 20,000Ks. I like the bluer lights and actinics give me headaches, so I use 20,000Ks. But, I am very clear that what I have is a display system, not a growth system.

Besides, if you need faster growth you can always feed more....

 

[Jasonf08]

Do you know of any photos showing the color difference? Im upgrading my hood with MH and have a choice in the bulbs also?

 

["Umm fish?"]

I can't find it at the moment, but I'd look for Sanjay Joshi's site on lights. Remember, nothing's going to look right on an uncalibrated computer monitor, but you can get the general idea.

 

[kinerson]

You can find some comparison of different 250w lamps in "lighting and filtration" towards the top of the page.

Umm, fish?,
Have you found your halides to show more "shimmer" without the actinics? My goal is a stable sytem with resonable growth rates and lots of shimmer and color.

Greg

 

[Random Aquarist]

http://www.marinedepot.com/aquarium_lighting_metal_halide_bulbs_information.asp?CartId=

 

["Umm fish?"]

I don't know what they look like with actinics. I don't use them. But, I do get lots of shimmer. But you can do the same thing by just putting an incandescent bulb over your tank.

Don't get me wrong, I'm a big fan of halides. They've proved that they can give enough light to anything photosynthetic we want to keep. But, they're expensive and they produce amazing amounts of heat. So, there are other ways to get shimmer if that's your only goal.

Is this for your 150? What are the tank measurements? Is there anything that you have to have that's going to be on your sandbed? I "needed" to have a clam and I wanted it on the bottom of my 2' deep tank so I could admire it all day. Right there, I needed halides. No other options.

I run 2 250W 20,000K Radium bulbs driven by Icecap electronic ballasts. I like the color and I'm happy with the growth rate. I have a frag tank if I want faster growth (although that has T5s , but it's only 1' deep).

 

[Tigger240]

just my experience, take this how ever you want

i ran a coralvue 14k, 10k, 20k, and xm 10k. i have coralvue ballasts. in all fairness my 20k never fired right on the ballast, i think it was sold as a 175 watt, but in reality was a 150 watt. i have a 175 (? 20k) 2-250's (cv 10k) and 2-400's(cv 14k and 2 cv 10k 1 xm 10k). in fairness the cv 14k, and 20k came with the lights i purchased. i only have bought 10k's new.

i dont run atinics or vho, just mh, and my bulbs are white. not yellow, or anything but white. i got a rant and rave when i purchased the coralvue bulbs (vs a reeflux bulb) from the seller and how i wouldnt be happy and this and that and that and this, i was like umm kay. i want 10k cv. expecting the bulb to be yellow (like ive seen some tanks) i was surprised to see it seem whiter than the 400w xm10k (this was my 250w). my cv 400w 10k didnt fire because the bulb was mismanufactured, so i have no idea how it compares to the xm 10k (400w vs 400w)

look up the ballast and bulb information - i found it after i purchased everything - d'oh

 

[kinerson]

I have a 150g 6 foot long 29" tall mixed reef with mostly softies and lps. I'm looking to keep lower to medium light needed livestock. I currently have a hamilton light fixture that can run up to 3-175w halides and 2-vho actinics. I have only been running the outside two halides along with the actinics. I notice that with just the halides on the shimmer is a lot more intense. I think I want to run all 3 halides and do away with the vho actinics. If I do this I want to try to keep roughly the same color light that I had with the combination. By doing this I hope to increase shimmer (which I love) and reduce wattage consumption by 185watts.

Greg

 

[Tigger240]

im not understanding if you run 2 mh (2x175) and 2 vho (guessing its 185w combined) but you run 3 mh (3x175) and no vho then youd only be reducing wattage by 10w. but it doesnt matter here anyways.

if you want display color then go 14k or 20k. 20k is blue and hardly any par, and 10k is lots of par and not blue.

searching is your friend.

 

[kinerson]

Currently i run 2x175w hallides (12k) and 2x180w vho actinics for a total of 710watts. I want to eliminate the two vho's and run 3x175w halides for a total of 525watts.

I just want to make sure the new display color is similar to the original color. The Iwasaki 15k has a PAR of 71 and a true color of 15215cct. Do you think 15k's will produce a nice bluish white color?

Greg