How Do I Tell If MH Bulbs Need to be Changed??

[woody189]

I recently bought a Sunpod fixture for my tank. It's 2 X 150 W Mh's.
I purchased it used, and IDK if the bulb were ever changed.
I'm a beginner w/ corals, and this is my 1st expensive piece of lighting. The problem is, IDK if I need to replace the bulb. I currently just have 1 mushroom in there, so I'm sure it's getting enough light, but how do I know if my bulbs aren't emitting as much useful light as they should? (assuming there is a way to tell)
I can't believe how expensive the bulbs are. Does the brand matter THAT much? Like I said, I'm a beginner reefer, so I don't know much. Would I be alright buying some real cheap bulbs for now, and upgrading to better ones in a year (when the bulbs need to be replaced anyway).
I would like to do it this way, because I know that since I'm starting out, I won't be able to tell the minor differences. I figure if it's okay, I'll cut a few corners now when I won't be able to notice.
What do you think? Thanks

 

[stanlalee]

you cant. in order to know when performance has declined enough for replacing you'd have had to test via lux or par meter when the bulbs were new or just after burn in then you'd replace them when you've determined the percentage has dropped significantly enough to warrant replacement. I'm not sure what the status quo range is (mainly because I'll never be doing that to care). If you dont have anything light demanding and the color hasn't shifted to being unpleasant to the eye keep them til your blue in the face. There are many tanks with 2yr old halide bulbs. you only care about drop off when you need the light or the color shifts to where you dont like it. with a mushroom I wouldn't worry about replacing bulbs til at least I got something more light demanding. Otherwise figure once every 9 month to a year is typical once you start with a new bulb.
And yes brand matters ALOT when it comes to halide bulbs. No name brands (and sometimes name brand) perform and/or look much worse than reputable offerings. you have to decide what kind of color you are looking for then find out which bulbs in that kelvin range and wattage your seeking perform well and people are satisfied with. And just because brand Y's 150 watt 10k bulb is great doesn't mean its 150 watt 15k bulb will be great. likewise just because brand A's 250w 15k is excellent doesn't mean its 175w 15k bulb is also excellent or even looks just like it. After you've searched the million threads on bulbs, read reviews and discover sanjays testing via google search (hint) by the time you are ready to replace your bulbs you'll have some choices narrowed down. I dont really find $60-90 per bulb (usually no more than 3) once a year that significant of an expense. Thats a family evening at outback with some drinks thrown down.

 

[woody189]

Originally Posted by Stanlalee
http:///forum/post/2993570
you cant. in order to know when performance has declined enough for replacing you'd have had to test via lux or par meter when the bulbs were new or just after burn in then you'd replace them when you've determined the percentage has dropped significantly enough to warrant replacement. I'm not sure what the status quo range is (mainly because I'll never be doing that to care). If you dont have anything light demanding and the color hasn't shifted to being unpleasant to the eye keep them til your blue in the face. There are many tanks with 2yr old halide bulbs. you only care about drop off when you need the light or the color shifts to where you dont like it. with a mushroom I wouldn't worry about replacing bulbs til at least I got something more light demanding. Otherwise figure once every 9 month to a year is typical once you start with a new bulb.
And yes brand matters ALOT when it comes to halide bulbs. No name brands (and sometimes name brand) perform and/or look much worse than reputable offerings. you have to decide what kind of color you are looking for then find out which bulbs in that kelvin range and wattage your seeking perform well and people are satisfied with. And just because brand Y's 150 watt 10k bulb is great doesn't mean its 150 watt 15k bulb will be great. likewise just because brand A's 250w 15k is excellent doesn't mean its 175w 15k bulb is also excellent or even looks just like it. After you've searched the million threads on bulbs, read reviews and discover sanjays testing via google search (hint) by the time you are ready to replace your bulbs you'll have some choices narrowed down. I dont really find $60-90 per bulb (usually no more than 3) once a year that significant of an expense. Thats a family evening at outback with some drinks thrown down.
Thanks for taking the time to give me all that useful info. You answered just about everything..

 

[bizzmoneyb]

i would just replace them anyway, this way you know exactly what youve got and how long they should last.
i wouldnt skimp out on the bulbs. i wouldnt skimp on ANYTHING in this hobby. it will only come around to bite you in the end.
im not sure on specific brands. i myself use a phoenix 14k bulb and am very happy with mine.

 

[t316]

I couldn't tell myself, so I just played the waiting game figuring I would replace one when it went out. But, I started noticing algea. It got worse and worse, and I couldn't put a finger on it as to why. Decided to change all the bulbs out and....

 

[woody189]

Well...
I've had the bulbs for probably a little over a month.
r
About 5 days ago, I turned my skimmer off for about 36 Hrs (I was away from home, and the cup was full)
When I got home, I had what I believe are diatoms on my sand bad. It's not as bad as I've seen, but it's still ugly.
Do you think it could be my bulbs? Probably another cause, but who knows.
My tanks been up and running for over a year BTW.
Originally Posted by T316
http:///forum/post/2994138
I couldn't tell myself, so I just played the waiting game figuring I would replace one when it went out. But, I started noticing algea. It got worse and worse, and I couldn't put a finger on it as to why. Decided to change all the bulbs out and....

What kind of algae did you get?
One more question...
Do the bulbs decline slowly, or do they just give out??
Like, does the beneficial light slowly start to fade away from purchase, or is it like over a short period of time (like a few day) that the light will drastically decline??

 

[stanlalee]

Originally Posted by woody189
http:///forum/post/2994405
One more question...
Do the bulbs decline slowly, or do they just give out??
Like, does the beneficial light slowly start to fade away from purchase, or is it like over a short period of time (like a few day) that the light will drastically decline??

they decline the most within the first few months then they decline VERY slowly. there's a significant difference between a new bulb and a year old bulb but there really isn't that much difference between a 6 month old bulb and a 12 month old bulb.

 

[woody189]

Originally Posted by Stanlalee
http:///forum/post/2994692
they decline the most within the first few months then they decline VERY slowly. there's a significant difference between a new bulb and a year old bulb but there really isn't that much difference between a 6 month old bulb and a 12 month old bulb.
Gotcha. THanks again.

 

[culp]

its vary hard to impossible to tell with just your eyes that the bulb is past it prime. that's why i just replace them one a year.

 

[ahren]

if you really want to read about lighting & bulbs google sanjay's lighting guide