lighting spectrum in a reef

[dakar]

Angel and I were actually discussing the lights last night, and considering the pros and cons of changing out the 2 250's with 400's when we hit the one year change out time for them in the spring. Gauging strictly off the color plots it could be a good thing to get a little better reach into the whole spectrum across the whole tank. Still undecided as yet, having the diverse lighting intensity areas by having the single 400 in the middle and a 250 on each side is serving us well. The added heat is another concern. We've got time to think about it.

If we keep gathering all of the plots we can find I'll try to find an easy way to compile them into some sort of easier to read graph, I'm sure I've got a program that will draw them up nice.

[davejnz]

I wish i could find some more spectral plots on VHO's,URI is known for there quality VHO bulbs yet i cant find one spectral plot on them or even find there website.T5's charts are pretty easy to find.Advanced Aquarist's online magazine has many of the MH's charts in its archives/back issues.

[davejnz]

I'm not sure how those tests were taken or can i explain why the blue wavelengths aren't penetrating as deeply.Your reasoning makes sense,but who knows.I do know that alot of corals are collected from lagoons that are near shore.
Read this article
http://advancedaquarist.com/issues/mar2002/feature2.htm

[dakar]

Did you find any explanation for the differences of the light penetration in coastal areas vs open water? (image diagram3_520_859 you posted above)

Why would the 550ish nm penetrate so much farther. I'd have to wonder if the measurements are skewed a bit. Coastal waters = high nutrients = higher concentrations of phytoplankton, algaes, etc = maybe they are seeing green/yellows at those depths since everything above would be filtering out the rest of the spectrum ? Or am I not holding my head right to see something different?

[dakar]

DOH! I hosed up the post sequence editing my poor spelling.

[EQCM2B]

In looking up stuff I came across this thread. As anyone who has helped me here in the last three weeks I have had a lot of questions about lighting. I have decided to go the way of a single 250 MH in home made canopy. The LFS was recommending EVC ballast and bulbs 250w @ 10k.I had not heard of the EVC line before andI didn't think the price was to bad so I figured I would look to you guys again for guidence.So again for my 46 gallon corner tank 22x22x13x13x13x25 tall, would this be a good combination to grow anything I wanted? I know there will always be somethings that it will probably be to much or to little still but for overall sps and lps, inverts and fishes. Has anyone heard anything bad about EVC bulbs or ballast?

Thanks for the help.

[davejnz]

I havn't heard much about either there ballasts or bulbs.The $ is usually the deciding factor when buying lights so i would shop around before buying.LFS usually jack up the price quite a bit compared to online retailers.How much are they asking for the whole setup?

[EQCM2B]

EVC 250 watt ballast was 145.00, I think EVC bulb 10k SE was about 65.00
Reflector and socket was about 50.00, I am still waiting for him to call me back because he did not have the price for them.

[davejnz]

Too much $ IMO,I would go with a 250 retro(e-ballast,bulb,socket,reflector) from CoralVue($180) or if your a DIY guy,buy a M58/H37 magnetic ballast off of e-bay(i paid $20 and $25 for both of mine),buy a time-tested/proven bulb($60-$80) like Iwasaki,Ushio,XM to name a few.And lastly get a reflector/socket($35).You will have to wire it up and install the components but its really not that difficult.

BTW,it might be better next time to just start a new thread as this doesn't really pertain to this one.

[EQCM2B]

Maybe I'll try that then. got plenty of time no need to rush.