Metal halide bulb

[CmLaracy]

Hello everyone. So my ADA 8000K bulb is getting quite old, and there's numerous pieces of evidence telling me it's on its way out. My scape is on a time contraint, so I cant afford to use it any longer than I have to. I ordered a new one but it won't be here until tuesday-thursday. I have a brand new, never burned 13000K that came with my fixture. I remember it was quite bright as it's the same model bulb that came with the fixture back in 2008 when I got it. I used it for a little while back then until I could afford an ADA bulb. This is a new bulb, just the same model.

Basically, I'd like some opinions on if I should leave the weak ADA bulb in or swap to the new and powerful, but incorrect spectrum 13kk. I know it has a good bit of blue in it, but I do vaguely remember it being a very high intensity bulb. I want to use whatever will get my plants growing faster until the new 8000K arrives. Normally it'd be no contest, the new bulb would be brighter, but I'm worried that the little bit of blue will make it so they both provide about the same amount of useable light.

Here's the journal in which I use the 13kk briefly, the growth seems like it was excellent:
http://www.plantedtank.net/forums/sh...t=57618&page=4

Note: I didn't swap to the metal halide until about 4 pages in (at 40 posts per page)

[rrastro]

My experience comes from hydroponics and, while the dispersion of light through water is different than through air, the bulbs are essentially the same.
Kelvin measurements are wishful thinking on the part of the mfr. Aquamedic doesn't even show their spectral output online, not the best sign. Their hype sounds good but that's about all I can say about it.
Generally speaking a newer bulb will have greater intensity than a worn out bulb and that difference may make up for spectral inadequacies.
How old is your old bulb and how much use (continuous/ on and off) does it have?
Considering your delivery date is next week I doubt it would make that much of a difference either way.

[CmLaracy]

Originally Posted by rrastro

My experience comes from hydroponics and, while the dispersion of light through water is different than through air, the bulbs are essentially the same.
Kelvin measurements are wishful thinking on the part of the mfr. Aquamedic doesn't even show their spectral output online, not the best sign. Their hype sounds good but that's about all I can say about it.
Generally speaking a newer bulb will have greater intensity than a worn out bulb and that difference may make up for spectral inadequacies.
How old is your old bulb and how much use (continuous/ on and off) does it have?
Considering your delivery date is next week I doubt it would make that much of a difference either way.

The ADA is definitely quite old, about a year and a half of burn. Usually I can induce algae with sloppy dosing, and I can't. Been trying to get some food going for my amanos. Also I usually cant look at my hand if I put it under the light, the reflection is blinding. Not anymore, I can stare right at it. Everything is growing, but the quality of growth is not what is usually is. My HC in particular, it's growing but not very flat/sideways.

The scape needs to be done in about 2 months, so whatever I can do to get things growing the fastest, I'll do. If it won't make any difference I wont bother because the fixture is a pain to get down and the bulbs are annoying to replace. The 13kk will definitely be brighter and more intense, whether or not I'll see a difference in growth in these next 4 days if I swap it in is another story. Also I've read the aquamedic bulbs are much more blue until they've had about 100 hours of burn, so that could also play a part.

I'm quite torn here.

[rrastro]

Wait a minute. When you say a year and a half of burn do you mean that much time of actual burn or that you've been using it that long on 8 hours / off 16 hours per day?
Regardless, if growth is your first priority, you need to switch bulbs now. I would've changed it at 9 months if strong growth is priority.

[CmLaracy]

Originally Posted by rrastro

Wait a minute. When you say a year and a half of burn do you mean that much time of actual burn or that you've been using it that long on 8 hours / off 16 hours per day?
Regardless, if growth is your first priority, you need to switch bulbs now. I would've changed it at 9 months if strong growth is priority.

about 12-18 months of 9-10 hours a day. And yeah fast growth is #1 priority. So basically the 13000K wont be detrimental enough to make swapping irrelevant.

Wish I had known this bulb was going before I started this scape. Thanks for the help, going to swap in the 13KK until the ADA 8000K 'green' arrives later in the week.

[shrimpNewbie]

Put I the 13000k while you wait, if you have red plants they'll thank you, I never fell for Ada halides personally although the color they put out is kind of pleasing to the eyes I would rather pay 13-25 for a bulb that will do what I need it to

[CmLaracy]

Originally Posted by shrimpNewbie

Put I the 13000k while you wait, if you have red plants they'll thank you, I never fell for Ada halides personally although the color they put out is kind of pleasing to the eyes I would rather pay 13-25 for a bulb that will do what I need it to

only green plants. I'd be ordering the normal ADA 8000K not the 'green' if I had any reds.

Thanks guys, will swap in the 13KK today.

[rrastro]

Originally Posted by shrimpNewbie

although the color they put out is kind of pleasing to the eyes I would rather pay 13-25 for a bulb that will do what I need it to

What he said.

After looking at the spec for the ADA bulbs I cannot come to any other conclusion. Their spectrum is skewed to accentuate green light which is essentially invisible to plants but theoretically pleasing to humans. PAR spectra are both above and below the green range, depending on plant and growth type. 130 bucks is waaaaaay too much for a 150MH bulb, IMO. I would stick with this 13K bulb you already have, return the ADA bulb, and buy cheaper bulbs every 6-9 months. It will be more cost effective and growth effective.

[shrimpNewbie]

Yup what he said I find my growth to be excellent with my 8000k and 10000k 70w bulbs from fish needit, they last long enough to please my needs and the cost is not even not note worthy. I myself prefer DIY LEDs but running a halide has been nice. My last recommendation is to return the Ada and buy several inexpensive bulbs

[CmLaracy]

Originally Posted by rrastro

What he said.

After looking at the spec for the ADA bulbs I cannot come to any other conclusion. Their spectrum is skewed to accentuate green light which is essentially invisible to plants but theoretically pleasing to humans. PAR spectra are both above and below the green range, depending on plant and growth type. 130 bucks is waaaaaay too much for a 150MH bulb, IMO. I would stick with this 13K bulb you already have, return the ADA bulb, and buy cheaper bulbs every 6-9 months. It will be more cost effective and growth effective.

Originally Posted by shrimpNewbie

Yup what he said I find my growth to be excellent with my 8000k and 10000k 70w bulbs from fish needit, they last long enough to please my needs and the cost is not even not note worthy. I myself prefer DIY LEDs but running a halide has been nice. My last recommendation is to return the Ada and buy several inexpensive bulbs

Good advice guys, I know exactly what you mean with the ADA bulbs. Unfortunately, I have fallen in love with the color provided by the ADA bulbs, I think they're worth every penny for how they make the tank look. And I get mine for $95 not $130. I can't decide if I want to stick with the normal ADA 8000K (which I love) or try out the 'green' version, as I only scape with green plants.

The 13KK is in the fixture, and my Aquasoil now has quite the purple tint to it. The plants are very washed out as well. All in all the tank looks quite strange. I'll post back here tonight to let you guys know if I see more pearling than usual, which I suspect I will.

Thanks a lot for all the help!

[rrastro]

Hah, I thought you might say that.
Aesthetics are very important to some people, especially ADA owners, but I could care less about how things look as long as they work.
Good luck!

[CmLaracy]

Originally Posted by rrastro

Hah, I thought you might say that.
Aesthetics are very important to some people, especially ADA owners, but I could care less about how things look as long as they work.
Good luck!

ADA customers are usually ADA customers because they care about aesthetics. If I didn't care about aesthetics I wouldn't bother buying a majority of the stuff I buy from them.

And I think even I would have a hard time shelling out $130 for a bulb, $95 is bad enough.

So, anyone with a 8000K 'green' want to chime in on its color? I've heard great things about it, and I've heard it's too green. I don't use reds so thats not a concern.