Combining different 400watt MH bulbs??

[M.E.Milz]

I am investigating lighting arrangements for a new reef tank (mostly sps) that will measure 80" x 32" x 36" high (with a 4"-6" DSB).

I do NOT want to use PC or VHO actinics, only MH bulbs. I am currently considering the following comination of five (5) 400watt MH bulbs spread across the width of the tank:

3x 400watt 6500K Iwasaki bulbs run on PFO's EYE (mercury vapor) ballasts, and
2x 400watt 20,000K Ushio bulbs run on PFO's standard ballasts.

All bulbs will be perpendicular to the front of the tank, with the Ushio bulbs spaced in between the Iwasaki bulbs.

Any comments or suggestions?

 

[Len]

Mike,

First off, I'm green with envy

Second, with a 80" tank and a bulb-to-bulb distance of 12", you're gonna notice the color gradients. I had 3 400 watters arranged in 20KK>6.5KK>20KK configurations, and with only a distance of 6" apart, I could still see pretty clearly defined spectral boundaries.

Why not actinics?

 

[canadawest]

While I do not currently use MH lamps, I have a couple questions.

1. Don't you think that 2000 watts of lighting is a bit overkill? Wouldn't that limit you to exclusively SPS and clams? Have you considered your power bill, as well as cooling requirements?

2. Instead of 800 watts of 20,000K (2 x 400W MH) why not use an Icecap 660 ballast with 3x60" URI Super-Actinic 03 lamps (3 x 140W) or 4x48" lamps (4 x 110W)?

Pros:
<UL TYPE=SQUARE><LI> Considerably lower power consumption
<LI> Considerably lower heat generation
<LI> Considerably lower equipment costs (2 x 20,000K MH lamps costs the same as the entire VHO setup w/ ballast, lamps, endcaps included)
<LI> Ability to simulate more gradual dawn/dusk by turning on VHO actinics before Halides come on and after halides go out.
</UL>

This would reduce your power consumption considerably, and the cost of the VHO actinic solution is much cheaper. (2 20,000K MH lamps alone will cost the same as the entire VHO setup)

Just my $0.02 worth.

[ October 03, 2001: Message edited by: canadawest ]

 

[Len]

Andrew,

2000 watts is definately not "overkill." Have you overlooked the size of his tank? It's monsterous.

I'm also a bit confused about your contradictory suggestion that VHO's initial equipment cost is less then that of the 2 MHs, yet also stating they cost the same.

Concerning the "better" dawn/dusk effect: I disagree. Unless your florescents are programed on a sloped dimming pattern, you won't get a better dawn/dusk effect then with just MH alone. Imagaine you're a little fishy, sleeping there all snug comfy. Then WHAM! 440 watts of light hits you when the VHO's turn on. Remember, fish can't differeniate between colors (and can't see the upper spectrums you and I can).

With MH, they're a gradual intensity slope inherent in its fireup design. I'd argue this is far more "natural" to your fishes, though less so to the hobbyist.

Mike,

I just read the other post. I think the 1000 watters is a better option then staggered, different bulbs. Unless you can let up on the actinic lighting issue ...

 

[M.E.Milz]

Here is my reasoning behind the current set-up, and answers to a few of the questions raised.

Is this too much light? I don't think so. I am currently using 3x 250watt 6500K MH's and 2x 6' VHO actinincs over my 200, which measures 84"x24"x24". The new tank will be about the same length, but 8" wider front to back and 12" deeper. The livestock will be moved from my 200 into the new tank, and will generally end up 12" deeper in the water column as compared to where it is now. To obtain the same lighting intensity at the lower depths, I will need 400watt 6500K MH's, particularly since the MH's will have to raised further above the water surface to get a even distribution across the width of the tank. I don't think that 10000K bulbs will give me enough punch to reach the lower areas of the tank. The only other alternative is 1000watt MH's, but then I would probably need 3 of these to get an even light distribution.

Why no actinics? 2 reasons. First, because the MH's will have to be position fairly high off the water surface, the actinics will probably be too high to do much good. I will also probably need at least 4x 6' VHO actinics to give me an even distribution of light. I am also concerned that the VHO actinics will not have enough intensity to reach the lower depths of the tank. Second, this tank will be in our living room, and my spouse has expressed dissatisfaction with the appearence of hoods or canopys sitting on or just above the top of the tank (one of a few concessions that I have made to get her to agree to the new tank

). In other words, I would prefer to minimize the overall dimensions of the light fixture, and keep the fixture spaced some distance above the tank, purely for aesthetic reasons.

As far as heat and light distribution, I was hoping that I can compensate for this by keeping the bulbs fairly high off of the water. Of course, I will have to use well designed reflectors to ensure that most/all of the light will be reflected into the tank.

Leonard, you raise a good point about seeing spectral boundaries between the bulbs. As I explained above, I had hoped that positioning the bulbs around 12" above the water, and by using high quality reflectors, I can take care of this, but I'm not positive. How high above the water were your lights positioned? Did you experiment with raising the lights higher?

Thanks, Mike

 

[M.E.Milz]

Leonard, I didn't read your 2nd post until after my previous post was posted. What would you suggest in the way of 1000watt MH's? My assumption is that 10,000K bulbs will give me an overall intensity that is comparable to 400watt 6500K Iwasakis (this is based on the assumption that 10,000K bulbs have about 1/2 of the lumens as compared to 6500k bulbs of the same wattage). I also assume that I will need 3 of these bulbs to ensure even light distribution, but maybe 2 will suffice.

I have not done any price shopping of 1000watt MH retro set-ups, but I would assume that the cost is probably comparable to the 5x 400watt option that I am also considering. Electricity, however, may be quite a bit more. Any idea on the amps that 1000watt MH's draw? Any suggestions on the best 1000watt ballast/bulb combination that does not require actinincs?

Thanks, Mike

 

[M.E.Milz]

Maybe I should ask people to post their preference on an exclusive MH (NO actinics)lighting combination for my new tank (80"x32"x36"high), using any combination of 400watt or 1000watt MH bulbs.

Opinions????

 

[Len]

My bulbs are always 10" above the water line, and aren't adjustable because of my canopy design. If raised to 18", the colors may blend better. Of course, this is pure speculation.

1000 watt halides draw close to 8 amps if we're to go by manufacturer's specs. This yields only about 900 watts of power, so either the power rating is inaccurate, or the amp rating is inaccurate. But then again, all these values vary from bulb to bulb, ballast to ballast. You'll definately need a larger circuit then the conventional 15-20 amp ones if you're planning on running 3 1000 watters. Regardless of number of 1000 watters used, you'll need the lights on a seperate, dedicated breaker. Same would go with 5 400 watters, so this is no big deal.

I've seen 1000 watt Ushios, and when used with a good reflector like the costly (but worthwhile) Diamondarcs, one bulb will cover 3' pretty effectively. You can get by with just two. Three would be better, of course; but the hassles it entails (3 would certainly use over 20 amps).

I've seen GE's 1000 watt bulbs, and they're not attractive. I've also seen Ushios, and they're a very nice, crisp white (better then the 400 watt versions, IMO). Much, much brighter (to the eye) then the Iwasaki 400 watters. Hopefully, someone will perform a lumen/PAR test on 1000 watt bulbs as they gain popularity.

I'd go with 2 1000 watt Ushios to beging with, and add a third if need be. Plan your electrical work around this to be safe.

 

[M.E.Milz]

Leonard, lets say for the sake of arguement that I will drop my prohibition against PC or VHO actinics. If this is the case, then I would be inclined to use 4x 400watt 6500K Iwasakis (driven by PFO EYE ballasts) & 4 96watt actinic PC's (driven by an Icecap 640 electronic ballast). Since all of the bulbs will be at least 12" above the water, the PC's probably won't do much beyond eliminating any yellow tint from the MH's, but maybe that is enough. Any thoughts or comments?

 

[wnfaknd]

i believe they dont make 640s anymore. unless you already have the ballast it may be hard to get a hold of one.

 

[M.E.Milz]

<BLOCKQUOTE><font size="1" face="Verdana, Helvetica, sans-serif">quote

believe they dont make 640s anymore. unless you already have the ballast it may be hard to get a hold of one.

I may have the wrong ballast number. But it probably doesn't make any difference since there are other ballasts that will drive 4x 96watt PC's, any it probably doesn't make any difference which type I use.

 

[wnfaknd]

yeah, you probably want the icecap 660.

 

[M.E.Milz]

Yep, that is the ballast I was thinking of. Do you know off hand whether it will drive 4-96 watt PC's? My assumption is yes.

 

[wnfaknd]

yep, they sure can run four 96 watters

 

[BerlinMethod.com]

Milz

I just bought a tank that is 72 inches long x 30 width x 24 deep. Initially, I plan to run 5-6 400 watts (10k and 20k mix). I also plan to add 2 1000 watters in the future after the price of electricity goes down and the tank is further established..

When you have the mixture of 10 and 20k, plus many halid bulbs to recreate the dawn/dusk effect (staggering the on times across the tank over 15-60 minutes), I think you get away without actinics.

Regards,
Kris

 

[Len]

12" of air won't attenuate much light (unless you have really dirty air

). If using a good reflector, your actinics will still serve a more-then-aesthetic purpose (i.e. provide PAR). My actinics are 8" above the water line, and provide oodles of light available for photosynthesis to the very bottom of my 24" tank. How's that for scientific quantification?

Think of it this way: If it's eliminating the yellow to the bottom of your tank, the actinics are reaching the bottom of your tank and providing additional PAR.

 

[canadawest]

Yes the Icecap 660 can run 4x96W PC lamps. Why PC lamps over VHO? Asthetically most people prefer the true actinic VHO lamps over the "blue" PC actinics, and so likely will your corals.

Len, in my post I stated that the entire VHO system initial cost is about the same as the 2 10,000K MH lamps only, NOT including the cost of the MH ballasts.

When you compare 4 VHO lamps + 1 Icecap 660 + endcaps it is FAR less expensive than 2 10,000K MH lamps + 2 MH ballasts + lamp fixtures.

 

[Sue Truett]

Just to add my .02 cents. I love my vho actinics over my pc actinics. I do have both in usage right now and plan on ditching the pc's when they run their usage. I have 2 160w vho actinics over my 180 ecosystem sps tank. I just like the flourescense{sp} you get with the vho's over the non with the pc's. I am using 2 96w pc. actinics in combination with my 2 400w 65k iwasaki's on my 120 and even this small amount of actinic lighting makes for very true white looking 400w iwasaki's. I sure want to see pics when you get your new tank up and running, Mike. Ought to kick a$$.

my 180 ecosystem sps tank: http://berlinmethod.com/suet/
my 120 sps tank: www.marshreef.org/members

 

[Len]

Ah. Gotcha.

The prices aren't that dissimiliar. A MH setup with 2 10kk's cost about $400. A 4 bulb VHO setup runs about $350. There's a difference, but it's not astronomical. But I don't wanna get into a spitting contest

I think I've used way too many graemlins in this thread

 

[Len]

Sue,

The PC's you're using doesn't sound like true actinics. They've recently introduced new PC bulbs in 96" lengths (as well as the former 55" bulb) that incorporate true actinic phosphors. These should be comparable to VHO's in regards to spectral output. Prior to this, the blue PC bulbs were simply standard florescent bulbs coated blue on the inside.