Scored Big!

[gman0526]

This is from iwan's thread who is the owner of the tank that was posted b4:

"I know the marketing argument that T5 lights are up to 3 years utilizable.

T5 lights can burn for a long time but the loss of the spectrum is too heavy for a stone coral keeping after around 9 months.

Bernd Mohr has described 1999/2000 the effect. After 9 months the growth stagnated. After a change of the lights the corals grew again very well. I know these for all T5 users change their lights in the interval from 6-11 months."

 

[liveforphysics]

Ok, the first thing you have to under stand is a simple and crucial property of light. Its called critical angle. If light hits salt water at an angle beyond 43deg, it can NOT penitrate into the water, it reflects off. So, start from 2 point sources, and try to work the angles out to illuminate a long rectangle. Use whatever reflectors you want, and whatever height you want. Go ahead and work the numbers on it an get back to me.


When you are done, work the numbers on trying to light a long rectangle tank by useing strips of light with reflectors. You will promptly discover that its magnitudes better for actaully putting light into the water, and at a useable angle.

As far as bulb life goes, its really a function of bulb heat and overdrive factor. I smoked a couple of normal output T5 bulbs in 2 weeks by pumping 600% of the power they are are rated for. Had I ran them at or below the rated power they could have gone multiple years.

Secondly, the frequency which the bulbs are energized with plays a big factor in bulb life. Quality and well designed ballasts will use frequencys that help bulbs to live longer.

But, lets say he is running 4 6ft T5 bulbs, and lets say he is really overdriving them on a cheap ballast and the bulbs are toast in 6months. So, at $20 per bulb (and fragman can get them for $16), you will be looking at 160$ in bulbs per year for the whole tank. Lets best case scenerio the halides at 1year per swap. The bulb costs could be cheaper this way with the halides, but the electricity cost difference will be more than compensateing. And once again, thats an exagerated worse case scenero thing, and you still come out ahead, plus you get all the added bennifts of having T5s that you dont get with MH.

If you have some bennifits for MH over T5, I would love hear them.

 

[liveforphysics]

This thread might help you.

http://www.reeffrontiers.com/forums/showthread.php?t=14411

 

[Scooterman]

Luke I think there are several benefits of MH over T5 H.O. & visa versa, I think a new thread on this would be interesting, IMO I'd like to use both for several reasons we could talk about there, maybe afterwards I'd rethink that but I haven't found enough information on T5's to truly compare. One thing I didn't see is comparison MH using L3 reflectors, same thoughts as improving T5's with good reflectors IMO this would change things. Oh yea in a 6ft tank I'd use three mh's not two.

 

[NaH2O]

Let's settle down a bit.

liveforphysics - why are you so set against MH lighting? They obviously work well, as there are many SPS keepers using them. I personally wouldn't keep SPS without them, and I don't, as the intensity will be different without MHs. There are some SPS that can do lower light (thinking of monti digitata as one), but in the long run (my opinion) I don't think you'd have a healthy coral that would withstand a stressor of somekind. I also feel you probably wouldn't see intense colorations, as you would with MHs. There is a lighting thread in the Great Threads forum (I know how much you love my links ) Let's Talk about ~Lighting~. Yes, you have SPS on your tank without MHs....however, IMO, you haven't had them in your tank long enough for me to say they are a success.

Let's get back to what this thread is all about....salmonslayer

salmonslayer - let's get this hammered out for you. Exactly what types of corals do you have interest in, and what do you think you'd like to keep in your tank? Also think about if you would ever want to keep an anemone. You don't have to have MHs if you don't want to keep SPS, but MHs would be beneficial to other high light loving critters like anemones and clams.

BTW, Great tank!

Posting photos can be frustrating... You were able to get the photo in your gallery, so now its a matter of getting the picture in the thread. What you do is click on the image in your gallery, then right click it to open the photo in its own window (not sure what the phrasing is in Windows - I use a Mac). I think you go to properties? You want to get the url for your image. Then you use the img tags in your post like this, putting the photo url in between the tags

:

(remove the *s)
[*img]http://www.reeffrontiers.com/photos_members/data/500/fish_tank_048.jpg[*/img]

looks like this without the *

 

[salmonslayer]

Sweet!, all you guys are great and thanks for all your imput. I have alot of planing to do at this time like what I will be putting in the tank. Also sump,holes I am going to drill & where, lighting, plumbing ect. The good thing about this site is you get alot of imput and advice. It all comes down to do I want to retro my canopy or leave it. many thanks to [liveforphysi & NaH20]

 

[MtnDewMan]

Some great info here, and some probably more than you were intending to get. It's all about what you want to keep. There are always more than one way to skin a cat so to speak. MHs are great for high lighting demand livestock, flourescent lighting for lower lighting demand livestock. And yes, there will be crossover where you can keep higher lighting demand livestock under lower lighting levels. There is a lot of evidence out there that MH lighting works great for SPS. And that VHOs and T5s can also work based on the type of coral that you are trying to keep. Soft coral of course do not demand the MH lighting intensity.

I don't think you are asking for the physics of angles of lighting attack and such as part of your original request, but to gain some opinions of others, that's what this is all about. For some reason I see things in here got turned into some kind of debate, I am not sure why. Everyone has their ways of lighting their tank based on experience, what has worked well for them, and other experts in the hobby. That's the beauty of this hobby, like I said in the beginning of my post, there is more than one way to skin the preverbial cat

 

[MikeS]

One thing I think people tend to forget when comparing T5's to MH is that on a watt/lumin output ratio, they are pretty equal. The thing is, in order to provide the same amount of lumins to the tank, you need to run an equal or slightly greater wattage of T5's. Since wattage ratings of a bulb really have more to do with power required to drive them than output, you are still using the same amount of power to produce equal amounts of light. And you will still lack the point intensity you get with MH's, which could be problematic in deeper tanks.

MikeS

 

[liveforphysics]

Nikki, Mike S- Its seriously time to stop perpetuateing a couple of myths. First, its time to stop saying that MH makes more intensity, as it completely depends on the setup. For a given amount of energy used, MH cant hang with the intensity that T5 makes, and the T5s can put it all the way across the tank. Personally, I think its pretty lame to have a couple of super intense patches about 1ft in diameter, while I'm trying to light a long rectangle.

Second myth you need to quit spreading is that MH is required for SPS corals to be healthy and colorful. Thats simply not the case at all, and its really a shame that you keep spreading that miss-information around.

Does MH work to light a SPS tank? Well, duh! Its definately the status-quo choice, and it does the job.

Is MH the best option? For a big round tank, often yes. For a long rectanlge, no its not, not by a long shot.

I dont know how to break it down here for you guys, but getting light from a point source to spread out evenly is a PITA, and you end up wasteing a ton of the light. Secondly, you dont get a remotely even lighting coverage, you get a few super intense places, and some places that dont get much. This is just reality.

Second reality, is that T5's have higher watts/lumen. That means for the electricity used, they create more light with it. Now, its only like around 15% more or so, so you neglect that if you want since its so small of an improvement. The big improvment comes from not being a point source, and how much better that means light can be put to use, and actaully reach the areas where your corals will sit, perticularly on a long tank.

So, do a little research please, or learn a little light physics, or whatever it takes, but perpetuateing this myth isnt a bennifit to anybody.

 

[MtnDewMan]

I didn't perpetuate any myth, I stated that other lighting will work for SPS as well. Please don't put words in my mouth.

 

[liveforphysics]

Sorry, I will remove your name from it, I ment to type Mike S in there. My mistake. I had no problem with your post.
-Luke

 

[jlehigh]

Regardless Luke do you have the studies measuring the output of t-5's in PAR, PPFD or Lux?

You are leaving a big piece of the puzzle out on the tank examples you are showing too. The SPS tanks running T-5's any achieving pastel colors are also using unique feeding and filtration methods that require significant commitment and detailed understanding of coral feeding, biology, and chemistry..

I left the T-5 bandwagon quite some time ago after seeing some measurments of the light output 16" below the water surface.

BTW saying MH achieve 1sq ft of intense light is far more mythical than the accusations and plees you have made.

So do some homework and present some informative studies with lighting measurements similar to what Sanjay does for us. I think it might be good to continue the discussion possibly in a lighting specific thread as well.

I also think these are mute points if an SPS only tank is not the long term goal here.

 

[JasonD]

Thanks guys the tank is 6'x18x24. Sounds like I should build a taller canopy. Trying to send pics. Found MH 400 watts each $250 for both, 0r icecap bal 660 for $140.VHOs I can leave my canopy and not have to mess with it.

It would be a shame to not use that canopy. It looks pretty sharp from the photo. You should be able to get a diy t-5 setup (4 or 6 x80watt) for under $300 (yes, good reflectors are a must). (I have been looking at t-5's for a new zoanthid frag system. I was thinking about a mix of 10k and true actinics. The goal would be amazing color with good growth.)

The only problem I see with that canopy (with t-5's) is access. It looks like it opens from the top, so you would have 24"+6"=30". Unless you have long arms, reaching the bottom of the tank is going to be a chore. A taller canopy with swing open front doors, would give better access. That is if your lighting choice was not in the way. I can't keep my hands out of water, so accessibility is a huge consideration for me. You might be able to set it up, so the whole canopy can be easily lifted. Just something to consider.

Jason

 

[Krish]

I ordered metal halides earlier this week and they were delivered yesterday to my freight forwarder in Florida, so I get them soon . I was just curious on one thing I see mentioned a lot and I figured I'd ask it here one time seeing it was mentioned in this thread as well. What is this PAR everyone talks about? I was told that dual 250w metal halides would have more PAR than dual 175's. Just curious what it meant. I'd go and search it, but that's less time I could be posting

 

[big t]

PAR = Photosynthetically Active Radiation
PPFD = Photosynthetic Photon Flux Density

 

[Krish]

Thanks Tom...Would that mean the more PAR you have (within the range if there is a range) the less hours of light (photoperiod) you would need in your tank per day to achieve photosynthesis? Or am I way off?

 

[Scooterman]

PAR can be related to punch! That is punch through the depths of water it penetrates.
In terms of our case that is.

 

[Krish]

Ahhh...More PAR is better for 24inch or deeper tanks! Cool...I thought PAR had something to do with golf why Tom answered seeing he's a golfer (or wishes he was)

 

[Scooterman]

Oh no you didn't go there LOL!
Man is it Friday yet? I need to go home!

 

[big t]

I am a golfer, and wish I was a good golfer. Hows that?