AheartlessFish

Im planning for my future tank which would be a 30x30x21 (90 gallon square) and the light source i plan to use is a metal halide unit (250watts of hqi double sided with x2 65watt compact fluorescent lighting) and 4 leds
I will be mainly aquascaping some HC or glosso

I know nothing about metal halide bulbs and how they work i just know they can get hot.
ive read the following article which states that they only lose 20-30% of intensity but i dont mind that...250 watts would become a 200ish watt bulb then ^^.
(http://reefkeeping.com/issues/2007-04/ac/index.php)
I dont wana read more articles i just wanted personal inputs on this topic.

i understand rex grigg believes that a bulb will grow plants as long as it lights up (aka no need to change it every 6-12 months)
and im strongly for that ^^

my question are:
whats the life span on these bulbs (as in until they blow or go out not until i should replace them due to wattage/spectrum loss)?

if i use a 10,000k bulb, and it loses spectrum over time....doesnt that just means it becomes a 9000k? or 8000k? etc.?

thanks

wwh2694

As for ADA Mh bulbs they recommend it to be change every 12 months. The PAR value goes down overtime and will make the plants grow slow. U want ur light to be low anyways easy to control co2 and fertz. Mh bulb will last for a long time but the ballast thats another story. Some ballast will not last as long as ur bulb some only last 2-3yrs other will last u 10yrs. The ballast the i bought from Fishneedit.com only last 2yrs. I got another one and it looks like they recalled it. Hope this one will last. Now the ADA ballast i have on my solar 1's, only used it for 9 months.

AheartlessFish

thanks alot for your imput...cause its really making me rethink...haha...
i will be buying a unit that has it built in...thats what i heard about the ballasts...they go out fast which is making me iffy...
i dont plan on buying a new light every 3 years...sounds expensive and lame.

gr33nthumb

wwh2694 has some very valid points, especially about the high/low light factor of MH lights. I run a 150w double ended over a 30 gallon and the light is the most brilliant, awesome light I have seen, displaying the tank unlike any other type of light. The drawback: the line between balanced and not is VERY thin with this much/type of light. Take into consideration how active you want to be with your setup: do you want to mess with it like a scientist, or do you want something That is more or less "set it and forget it?" Thats partly how I made my decision, hope it helps you some!

AheartlessFish

when i had my 100 gallon setup, i ended up messing with it like a scientist 2 hours + a day (on free days of course which was almost everyday)...
i got tired of messing around with a fully planted tank (like stocked to the max with only 1/3 of the tank was swim space). So I only play with carpeting plants now and keep the long stem plants to a low amount that is prune-able yet gives plenty of swim space for fish i find doing this = less maintenance.
If only hygrophilia polysperma sold for big bucks O.O! i think its illegal in the trade tho :P

I think im gona end up with t5ho due to price managability and the negativity im getting from halides (cost wise)

gr33nthumb

That's awesome, I happen to be a Hygro lover myself! If its hygro species I want to grow it!

I love and prefer the scientist route for sure, its what the hobby is all about for myself. If cost is an issue I would check this link out: http://www.fishneedit.com/metal-halide.html The 150w silver pendant is what I ended up picking up off craigslist for $60, plus 6500k bulbs I found for $20. The prices on that site are not bad at all and the quality of the thing when I got it and tore it apart is exceeded my expectations for sure. Yes, I am slightly MH biased

AheartlessFish

haha im same

if im gona get it, its gona come off of craigslist!! hhaha i refuse to pay 500% markup pricing on lights! craigslist has been doing me very well on all my fish stuff

gr33nthumb

It really has for me aswell, as like yourself, I cant fathom spending $200+ on a fixture I could have made for $40 at home depot! Crazy part is, when you tear into one of those fixtures there is NOT $200+ worth of components! Craigslist for the win, and good luck on picking your lighting!