View Full Version : VHO and MH Color spectrum questions?

02/02/2011, 10:40 AM
On my 125g, I run a canopy with 2 VHO bulbs for actinics and 3 MH bulbs.
2 X250 W and 1 X 400W.

The previous owner ran the 2 X 250s for 4 -5 hours and the 1 X 400W MH for 4 - 5 hours. The VHO bulbs were ran for 10 hours.

This is what I'm doing also, and seems to work fine.

My question is related to bulb color spectrums.

The VHO bulbs are used for actinics and emit large purple hue and I noticed the bulbs have a puprle coloring to them. I was hoping to mix these up a bit kind like one mixes up T 5 bulbs...

Is there a such thing as a VHO bulb that would have a blue coloration to it? So, I could maybe run both a blue and a purple bulb or something like that?

As far as the MHs, all 3 bulbs I believe are 10k SE bulbs. I have heard it said that 20k bulbs have a nicer look to them. Would they bring out a blue hint to the tank more? I've got tons of purple coraline on the rocks, with the MH and purple VHOs, the tank is overpowering purple. I would like to mix more blue color into it.

When I did a 35% water change with Reef Crystals, I got a beautiful blue hue to the tank for about 1 day. I assume as the salt dissapated into the water whatever colored it blue diminished.

Any thoughts on bulb combinations of VHO to MH bulbs that would look really good?

If so? Who sells them and where do I find them?

I haven't seen any "colored" VHO bulbs for sale online, but, I've only started looking.


02/02/2011, 11:29 AM
You can try and find a VHO bulb with a lower nm something like "420nm".
I have 420 which are pretty blue and 460nm which are purple. These are in T5's though. Usually the higher the nm the more purple they are. Or possibly a combo bulb? http://www.marinedepot.com/UVL_72_Inch_160W_Actinic_White_VHO_T12_Fluorescent_Bulb_VHO_Fluorescent_Light_Bulbs-UV_Lighting_Company_(UVL)-UF3243-FILTBUFLVB-UF3723-vi.html
Yes a 20K MH bulb will be much more blue.

02/02/2011, 01:47 PM
Thanks for the information. that's helpful!! I'll be using this in making my decisions.

Thanks! Anyone that uses these bulbs that really likes them or any major complaints?

02/02/2011, 03:39 PM
Hi Travis,

Actually the 450 nm range is bluer and the 420 is more purple (or violet) as it tends towards the ultraviolet end of the spectrum. (see link below)

The UVL blue 454 lamp is bluer.


The Hamilton VHO actinics are blue instead of the purpleish color of the super actinicRs.

Adding one 50/50 URI tube will remove most of the purplish tint to the eye, but it will still be there to give the coral pigments that flourescence.

When I ran MH and VHOs, I ran two superactinic Rs and two 50/50 for 12 hours and the MHs for eigth hours.

As far as combinations for what looks good, its largely personal preference.

I really liked Radium MHs with URI super actinnics, Coral Vue 12K with Super Actinics, and for cheap XM 20 K with two super actinics and two 50/50. If you lik blue., you might try this last one with one superR and one 50/50.

Lastly, your water change exmeplified that water clarity can make a big difference when it come to the blue hue. If there is any yellow to the water, try using more carbon. Take a clear drinking glass scoop out a half glass of tank water and hold it in front of a white background. Use a glass of freshly mixed SW to compare. If the tank water glass is yellowish, increase skimming, carbon and water changes to get the organics level down.

02/03/2011, 07:35 PM
10K metal halides + VHO's is a great look. I ran that for years and loved it. It is the best lighting available in my opinion. Great for growth, color and shimmer effect.

You could try the 454 Blue bulbs from URI (UV lighting now). They are more of a royal blue color. So, if you want more blue and less purple, try those.

Champion sells them.