Help with choice of lighting (DE or SE)

[gpodio]

I've completed building a canopy for my 40 gallon stretch-hex and have a BlueLine 250W MH ballast to drive my lighting.

Now that I have to buy the socket and bulb, I'm having difficulties deciding between HQI or SE bulbs. The HQI would certainly free up some much needed realstate in the hood. But from what I've read, these bulbs need a UV filter, right? If so, the tank's original glass lids are the best I have, and if possible I'd even go without these if that won't preset any problems.

I think either the SE or DE bulbs will put out enough light for this tank so intensity is not something I'm concerned about. I've never used a HQI bulb before so not really sure on the dos and don't of these lamps. Anyone running them unshielded in a canopy? Anyone else using the BlueLine e-ballast to drive a HQI bulb?

Thanks

[musashi666]

Going to tag along on this one too as I'm in the same situation...
only w/ a 2' center section of a 125 AGA.

[North Bay 101]

The DE bulbs must be shielded. The DE bulbs will be more intense than the SE counterpart. It depends on what you want to grow in your tank as to what type of bulbs you should run. I am running 3 250 watt DE pendants and I have plenty of light. There are more choices when you go with the SE compared to the DE bulbs and DE bulbs are a bit more pricey but they are supposed to last longer. It sounds like I gave you more questions than answers, sorry about that.

[Steven Pro]

Sanjay Joshi has done a lot of testing of various MH lamps, ballasts, and reflectors and generally the DE lamps provide more light with less electrical consumption than SE models. If you search www.AdvancedAquarist.com you should be able to find Sanjay articles.

[gpodio]

Thanks guys, I did read Sanjay's articles last night and noticed the warning about using these lights without a shield. I guess that's the breaking point for me as that would complicate the canopy more so than using an unshielded SE bulb. Regarding intensity, I believe it is of less importance in my case as even a SE bulb in such a small tank should allow me to grow many things without too many limitations.

On a slightly different topic, I hear most people who have actinics use 10K bulbs. My friend is advising me to get a higher kelvin bulb regardless of the actinics (2x55W 03 Actinics + 250W MH). Are many people using higher temp bulbs WITH actinics as well? Besides the estetics, what are the effects on coral growth? I'm considering 12K-15K but unfortunately have no tanks to look at to compare. I've been looking at Joe's wonderful MH comparison but to my eyes the CV12K looks more blue than the CV15K :-) Not sure if it's my eyes, my monitor or something else...

Is the resulting effect similar to just having more actinics?

Thanks for the help!

[Eryl Flynn]

I would not go DE if the only sheild you are going to use is a glass cover on the tank. Yes it will protect the fish and corals, but what about your self? Any time you open the hood you either have to turn the light off, or risk a sunburn. I feel the risk and limitations you would have to deal with are not worth it.