Metal Halide Q&A

Possibly. Depends on a couple of factors.

Is it going in a hood or pendant?
Active cooling?
Splash shield?
Ambient temp?
Wattage to be added?

All of these play a part in total heat added to the system.

 

If you are interested in information on most common ballast/bulb combos I can supply bulb output, CCT (aka kelvin), or a spectral irradiance plot of your bulb.

Just list your ballast and bulb and what you would like to know.

 

next question

whilst using T5s, it was recommended to me to use a ratio of 1:1 actinic and white tubes
as the symbiotic algae living in corals benefit from the actinic output
with 6 x 80 watt tubes its easy to achieve the 1:1 ratio

but with 2 x 250 watt MH , how do you achieve a 1:1 ratio with actinic when you could probably only add an additional 2 x T5s to most canopies that have MH lamp

thus the question is - is actinic supplementation less important due to to higher PAR created by the MH lamps?

Steve

 

Is it going in a hood or pendant? pendant
Active cooling? you mean a chiller? no chiller
Splash shield? on the pendant yes
Ambient temp? ?
Wattage to be added? have 130w of pc think 250 MH

 

I have seen several SPS dominate tanks that run solely MHs. No supplementation. They looked fantastic.

Not sure on the science of it. Just assuming that they provide very well what is needed to grow.

I am also going to assume that a cheap bulb is not an option in this case. That may be some of the reason for supplements. They are not happy with the MH bulb, but are unable to correct it to satisfaction.

just a guess though

 

i like Steve's question...

 

Active cooling could be several things. Fan mounted in canopy/pendant. Fan mounted on sump, or a chiller.

Ambient temp: The temperature of the room the tank is in. Is the room normally hot / cold? Do you have an A/C in that particular room. Does it get lots of southern light?


Personally, I think if you had a fan on the pendant and good cooling in the room then you will see minimal temperature differences in your tank.

I am running 1000Watts of halide on my tank and see 2 degrees of temp difference. This is achieved by proper cooling of the pendants.

 

I love MH lighting. The shimmer gives a great amount of life to the tank IMO.

 

Steve, we can look at this spectral analysis to determine what will be helpful to your zooxanthellae



Now as you can see, there are very specific peaks produced by this bulb.
The peaks are at 420nm (UVA radiation which really makes your corals pop), 540nm (excites the fluorescent green chromoproteins), and another at 580nm (for excitation of green).

These peaks supplement the corals in a way that the actinics do

 

thank you Dingo (and Jonjon who also helped with my questions)

Ill try not to thread hog, but I am interested in this subject

would this indicate that 1000k temp MH lamps alone would be adequate for corals , mostly SPS
is there any benefit from using the higher Kelvin temperature lamps (other than aesthetics?)

Steve