Quick MH/PC lighting question...

[jjwill_sdsu]

Hi all, just a quick question (but long responses are welcome ) about MH versus PC lighting...

When I usually ask about how much lighting I would need for a particular coral/clam/anemone/etc., I usually hear a recommendation for MH lighting. Is MH necessarily that much stronger than PC's, or is it simply easier to fit 250 W into a single MH bulb rather than 4 PC bulbs, i.e. does 250 W MH = 250 W PC lighting? I currently have a 260 W PC fixture on my 72 gallon bowfront, and I was wondering just how much I would need to upgrade to put myself in the market for some of the more light demanding species.

Okay, so it wasn't exactly a quick question, but I would appreciate any insight.

Jordan

 

[DrBDC]

It has to do with the PAR/ppfd output of the bulbs. PC's barely put out any and really only work with softies and "some" LPS that are lower light. Some sps can live but not thrive under pc's such as some montipora's. It would probably be easier to have a tank work with 250 watts mh than 500 watts pc's. That response too depends on the mh bulb chosen. Some are so low in par output they probably aren't much better than pc's. It's all in the PAR/ppfd output levels. Instead of a watts per gallon approach it should be in ppfd per gallon.

 

[MayoBoy]

The other option would be t-5s which are more comprable to MH but are easier to fit into a hood (like PCs). If you go T-5, be sure to use a single reflector per bulb, not a single reflector for the hood.

 

[Mykayel]

there's a webpage (that I can't find) that list the light output for different MH blubs and ballasts.

Something I've really like since I've switched to MH is the shimmer lines that you get that you won't have with any other lighting.

 

[MayoBoy]

http://www.reefcentral.com/forums/showthread.php?s=&threadid=624185

 

[DrBDC]

Here is the link to a bunch of them in an easy read chart:

http://www.cnidarianreef.com/lamps.cfm

Here is Sanjays reef lighting page where you can plug in the bulb and ballast for 2 different combos and see where the color spectrum peaks as well as give par/ppfd readings:

http://www.reeflightinginfo.arvixe.com/select2lamp.php

 

[DrBDC]

BTW, don't use the pictures on that first link for a true color representation. That depends on monitor, camera, etc. etc. etc. IME they are completely different looking that true life, at least on the XM10,000K bulbs.

 

[jjwill_sdsu]

How much MH would you recommend for my tank (72 gal bowfront)? I would like to try my hand with some clams (derasa or perhaps crocea), maybe a bubble tip anemone, and some SPS would be nice as well. Would you recommend supplementing the MH with PC's for actinic, or will the MH be fine on its own? Thanks for your help.

Jordan

 

[MayoBoy]

You could go with 2 175s or 250s only or add some PCs, T-5s or VHO's for dusk/dawn. It kind of depends upon your budget, do you want to go DIY or plug-and-play, etc.

 

[jjwill_sdsu]

I would like to keep this on the low end of the budget spectrum and stick with plug-and-play if possible. Adding PC/T-5/VHO for dusk/dawn would be nice, but not essential in my eyes. Do they offer any aesthetic or healthful benefit during the majority of the lighting time while the MH's are on, and does adding dusk/dawn add anything besides a coolness factor? Thanks.

Jordan

 

[MayoBoy]

I have 2x175 MH (10,000K & 14,000K) and 2x65 actinic PCs on my 65. The PC's (besides the dusk to dawn) add nice coloration/fluorescence without having to have the ultra blue of 20,000K bulbs.

It's a personal choice. The best way is to see some tanks in person so you can decide which look you like the best.

 

[chadfarmer]

on a 72 gallon you have to get 2 metal halides for the tank

150, 175, 250, doesnt matter

if it was me i would look at the metal halide and let me tell you they put off heat and the high from the water they are the less intensity you lose)

also look inthe the tek light in 48 length (either the 4 or 6 bulbs would be great on your tank)

t5 you can costomize the color and you can also keep clams under them without starting them to death (not even close to as hot as a metal halide gets