Getting Down to the Nitty-Gritty on Lighting

MrSpectrum

Gray-bearded Member
The enclosure I'm building will be 60"W (inside to inside) x 24"D (inside to inside) x 23¾"H (finished floor to ceiling). Actual outside height 36". There is an 8"H space for concealing the lighting fixtures, wiring, ventilation, etc.

The "false" ceiling I'll be installing the lighting in measures 60"L x 24"D.
Fixtures will be mounted on top of this ceiling, creating essentially, "recessed lighting" throughout the enclosure. This also provides sufficient distance between the T5 10.0 UV-B tube and the basking area.
I'm considering changing the plan from a 48" T5 fixture to a 36" T5 fixture (UV-B). My only concern here is that there will be a 12" gap at either end of the 36" T5 (assuming it's centered) that will get less UV-B (perhaps this is not an issue?)

Basking light will be a recessed eyeball fixture--a single one of these: https://www.homedepot.com/p/Commerc...ed-Eyeball-Trim-6-Pack-CAT603WH-6PK/202057590
because it was the only eyeball they had that would still take an incandescent flood (everything else was LED ONLY).

I'm also considering some kind of supplemental general-purpose lighting--either another recessed (but not necessarily aimable eyeball) fixture OR a dual T5 fluorescent fixture, one tube being the UV-B, the other tube being more broad-spectrum.

My assumptions thus far are that the T5 fixture should be centered longitudinally and latitudinally, with the basking fixture between it and one side of the enclosure. If the supplemental lighting is incandescent, fixture placement would mirror the basking fixture. If supplemental lighting is via a second tube, well, that's established, and one side (the cool side) of the enclosure may be slightly dimmer than the basking side.

Any thoughts/comments/recommendations, either general or specific?

Thanks

EDIT: Changed inside height of enclosure. The floor will be rather heavy with the slate tile floor added (already figured in to calculations) but rather than having the plywood enclosure bottom rest directly on the table/base, I'm raising it up 1½" (resting it on 1 x 2 "joists") to provide better attachment to enclosure sides and more integrity/stability overall.
 

Claudiusx

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MrSpectrum":1tjc7ixy said:
My only concern here is that there will be a 12" gap at either end of the 36" T5 (assuming it's centered) that will get less UV-B (perhaps this is not an issue?)

You should bias the uv to one side. It should be up against the hot side, and extend over to the cool side. This allows for a nice uv gradient, and for the lowest uv exposure in the tank to be at the cool end. Lower uv and cooler temps go hand in hand and mimic the wild more. Naturally, they would go somewhere with shade cover to cool down, which would have lower uv exposure. And naturally, where they bask should have the highest uv exposure in the tank.

As far as front to back goes, I center it over the basking area. But it's not the biggest deal. The placement side to side is more important imo.

In regards to supplemental lighting, it might be a good idea simply since your tank is so large. I still tend to like the shade method for the cool end, so I personally dont mind a bit lower lux on that end (all this is with gradients of course) but you could definitely use either a low wattage incandescent (might not be too bright at a low wattage) or you can be my Guinea pig and buy that LED array I found :laughing6:

-Brandon
 

MrSpectrum

Gray-bearded Member
Original Poster
claudiusx":29o9b9xg said:
You should bias the uv to one side.
There's not a lot of space to do that; if I keep the eyeball centered longitudinally (in-line with the tube) the closest I can get it to the hot side wall is ~8".

It should be up against the hot side, and extend over to the cool side. This allows for a nice uv gradient, and for the lowest uv exposure in the tank to be at the cool end. Lower uv and cooler temps go hand in hand and mimic the wild more. Naturally, they would go somewhere with shade cover to cool down, which would have lower uv exposure. And naturally, where they bask should have the highest uv exposure in the tank.
Wait... your WHAT hurts I'm befused. :?
If the tube extends over to the cool side, it sounds like I should go back to the 48" fixture(?) Skewing the 36" tube toward the hot side leaves 16" w/o UV-B on the cool side. Is that what you're suggesting :?:

In regards to supplemental lighting, it might be a good idea simply since your tank is so large. I still tend to like the shade method for the cool end, so I personally dont mind a bit lower lux on that end (all this is with gradients of course) but you could definitely use either a low wattage incandescent (might not be too bright at a low wattage) or you can be my Guinea pig and buy that LED array I found :laughing6:
That's why I was thinking of using a second tube. Tube or bulb, since the objective here is light and not heat, I was thinking (hoping) to go with some kind of LED to save energy.
 

Claudiusx

BD.org Sicko
Staff member
Moderator
The basking light and uv tube dont need to be in the same line. You can have them side by side. I'm on mobile so prepare to be amazed by my drawing skills.

They can be like this:

---uvlight---
(B)

As opposed to this:
(B)---uvlight---

By extend to the cool end I just meant start at the hot side and it extends straight over. It doesnt need to go all the way over to the cool end I think you asked awhile ago and I told you I'd personally go with the 36, but either will work.

16 inches without uv on the cool side is fine. The tube doesnt only shoot its rays straight down, some will go out sideways and allow for a gradient. And in such a large tank anyways, you're still providing a ton of areas with a lot of uv exposure.

Remember uv is good. Uv is also bad. They need areas to escape from it and there is no reason to make that area only 10% of the tank.

FWIW I use the 22s in my 4x2x2s.

-Brandon
 

MrSpectrum

Gray-bearded Member
Original Poster
claudiusx":3u7qaptv said:
The basking light and uv tube dont need to be in the same line. You can have them side by side. I'm on mobile so prepare to be amazed by my drawing skills.

They can be like this:

---uvlight---
(B)

As opposed to this:
(B)---uvlight---
IC. Unfortunately, that throws off what I had envisioned. :( Have to cogitate on that.

By extend to the cool end I just meant start at the hot side and it extends straight over. It doesnt need to go all the way over to the cool end I think you asked awhile ago and I told you I'd personally go with the 36, but either will work.

16 inches without uv on the cool side is fine.
Yes, we discussed it. I keep flip-flopping in my own mind. Chalk it up to novice uncertainty (and I haven't even got the bloomin' lizard yet! :lol: )

If I scootch the tube all the way over to the hot side, that'll leave 24" w/o UV-B. I know the tube doesn't shoot straight down. Regardless, the vector will place the distance even farther than the ~26" straight down.

Remember uv is good. Uv is also bad. They need areas to escape from it and there is no reason to make that area only 10% of the tank.
OK, 2 things.
1. Even if the tube extended over the cool side, the zard can escape it by going into a hide, though I'm not sure he would even need to, because...
According to experts, the optimal UVI gradient for a bearded dragon is 0 to 4.0-6.0, from lowest (furthest from the bulb) to highest (basking area). Most normally pigmented bearded dragons can tolerate UVI of up to 7.0 safely, but these levels are not necessary in captivity for optimal health.
https://www.reptifiles.com/bearded-dragon-care-packet/bearded-dragon-temperatures-uvb/
According to Reptisun's table, a 10.0 T5 produces 2.6-3.5 UVI at 5".
https://zoomed.com/wp-content/uploads/Choosing-Correct-UVB-Lamp-2018-07.pdf

2. Everything I've read has said that artificial UV--even a 10.0--is nowhere near the intensity of sunlight, and it'd be nigh impossible to provide too much in an enclosure unless it was literally right on top of the lizard, which it wouldn't be. Basking level will be where it should be (Recall I'm getting a UV meter) and at floor/hide level, distance from floor to UV bulb will be ~26" or more. Again, according to Reptisun's table, at that distance he'd be getting < 0.5 UVI. I'm not sure it'll even reach him. :dontknow:

Not trying to be difficult/argumentative. I need to feel comfortable/confident in my decisions/choices. Hope you can understand that. :)
 

Claudiusx

BD.org Sicko
Staff member
Moderator
MrSpectrum":2mnfxbrp said:
Not trying to be difficult/argumentative. I need to feel comfortable/confident in my decisions/choices. Hope you can understand that.

You're not at all and I dont take it that way. We are the same in the way where we want to understand it ourselves and we want it to make sense to ourselves, not just be told it makes sense.
I completely understand.
MrSpectrum":2mnfxbrp said:
According to Reptisun's table, a 10.0 T5 produces 2.6-3.5 UVI at 5".
That number has to be without a reflector as weve tested that bulb many times and its differently stronger than that. The reflector basically doubles the output, which lines up with our suggestion of having the bulb be 10 to 12 inches away for the t5 + reflector.
So if you used a reflector, even at a distance of 25ish youd be getting around .5-1 uvi I believe. I'd have to double check. But that's ok.

FWIW dr Francis believes 3 uvi is a good level for most species. Then we have the Ferguson zones which state slightly higher. And Arcadia states around 4-6 I believe.
I tend to fall in the middle and feel that 3 is a good number, but providing an area slightly higher for if they choose to is good too. 3-5 is what i like.

MrSpectrum":2mnfxbrp said:
Everything I've read has said that artificial UV--even a 10.0--is nowhere near the intensity of sunlight, and it'd be nigh impossible to provide too much in an enclosure unless it was literally right on top of the lizard,
This is mainly correct. They are no where near the intensity of the sun, but that's not to say that they are not intense. They do have the capabilities of causing serious harm. Most consider exposing them to constant levels over 7 in a tank is dangerous. 10 is really dangerous, and the higher you go the worse it gets. Of course they can get over these levels in the wild. But there is a big difference between 14 hours a day exposure and a few minutes of exposure in the wild.

Not even speaking specifically of reptiles here, but uv, especially shorter wavelengths such as uvb and uvc are extremely damaging to living organisms. It makes sense in my mind that the goal should be to provide them with just what they need, and not any more. We unfortunately dont know exactly how much they need, but we can go off experience. And experiences have showed us that even the seemingly now-labled puney t8s had always worked for us in the past. Dragons weren't suffering from metabolic issues due to lack of vitamin d when housed properly under these bulbs. So we know that at least what dr Francis suggests of a uvi of 3 being sufficient, as it's around what we all used to give with our t8s. Sometimes less.
It also makes sense to me that there is no reason that they need to be exposed to uv for the whole day. It doesnt need to be at measurable levels throughout the whole tank. They mainly need it at their basking site.

And if we think about it in a different way, what possible harm will come to them from having 0 uvi in half of their tanks? (Not what I do or suggest, just for purposes of discussion)
Well really the only thing you'd imagine could go wrong is that they wont get enough vitamin d3.
However, the body will only synthesize so much d3 in the skin before it stops. this is the case with natural sunlight but we dont know this for fact to be the case with artificial light.

I guess what I'm trying to say is, I dont see there being any issues with providing areas of no uvi in the tank. Yes a hide will accomplish that too, but I don't necessarily agree with making the dragon hide to escape the rays if it so chooses.

Sorry I'm on lunch at work so my thoughts are all over the place and I probably didnt get what I was trying to say across as well as I would have if I was at home.

If I'm confusing just say so and I'll clear things up later lol.

-Brandon
 

MrSpectrum

Gray-bearded Member
Original Poster
claudiusx":11oxshqm said:
FWIW dr Francis believes 3 uvi is a good level for most species. Then we have the Ferguson zones which state slightly higher. And Arcadia states around 4-6 I believe.
I tend to fall in the middle and feel that 3 is a good number, but providing an area slightly higher for if they choose to is good too. 3-5 is what i like.
Those numbers are in line with Reptisun's tables.

Most consider exposing them to constant levels over 7 in a tank is dangerous.
Right. So says Reptisun (not necessarily relying on their word as gospel, but so far, their numbers aren't out of line).

Between the placement of the primary basking spot, mounting of the lamp above ceiling level, height of the tank, and using the UV meter, I'm not really concerned about too much UV. I'll make sure he won't get anywhere near 7--most likely no more than 5, and easily get away from that to other spots.

It also makes sense to me that there is no reason that they need to be exposed to uv for the whole day. It doesnt need to be at measurable levels throughout the whole tank. They mainly need it at their basking site.
I don't disagree. The plan (currently) is to have the basking light on 14 hours, and turn the UV on 2 hrs after the basking light, and off 2 hrs before the basking light goes off. I understand there may be seasonal adjustments to those figures.

Whilst cogitating, it occurred to me that there shouldn't necessarily be a problem with mounting the basking light in line with the UV tube. As you said yourself, "The tube doesnt only shoot its rays straight down, some will go out sideways..." I think it'll boil down to what the UV meter says, and adjust the basking spot accordingly. Besides, since the basking fixture is aimable, the angle will be the exact same whether it's in line with the tube, or mounted alongside it.

Everything else seems like a good argument for the 36" fixture. I'll go over what I've bookmarked again.

Thanks.
 

Claudiusx

BD.org Sicko
Staff member
Moderator
You could do that in regards to the UV timing, but that wasnt really the point I was trying to get across. My point was that you dont need to provide uv in the entire tank because they don't have to have exposure to it for their whole waking hours. Areas of low uvb are good. And areas of no uvb are good too. That's what I meant by the comment they dont need to be exposed to it all day. Which is what would happen if the whole tank had uvb exposure.

Personal preference. But I think it makes sense to not force them to be exposed all day (even if it's very very low amounts on the cool end). Imo the cool end should have areas of 0.

-Brandon
 

MrSpectrum

Gray-bearded Member
Original Poster
MrSpectrum":pmryu2xl said:
I'm also considering .... a dual T5 fluorescent fixture, one tube being the UV-B, the other tube being more broad-spectrum.
Well, that idea crashed & burned; Sunblaster doesn't make (that I can find/tell) a 36" double T5 fixture w/reflectors. :(

Also had to scrap plans to raise the floor 1½". The back rests on the floor, which would then stick up preventing the top from going on. This is not a killer, though I may have to attach the sides to the floor with a few extra screws.

That dual 36" T5 unit has me stumped though--I really don't want to use 2 separate units.
 

MrSpectrum

Gray-bearded Member
Original Poster
Thanks for the link. Yeah, those are either too short or too long--can't tell if there's a reflector or not. My point was (and I wasn't clear) that it's back to the drawing utility (though I still have a drawing board :D ) with regard to finding a dual 36" T5 with reflector(s). I'll get to the searching--just been tied up with life's vicissitudes. :mrgreen:
 

Claudiusx

BD.org Sicko
Staff member
Moderator
That one linked does have a reflector, but its downside (or upside depending on how you look at it) is it's a remote mounted ballast - the ballast isnt self contained in the fixture itself.

I thought I linked you the 36inch model

-Brandon
 

MrSpectrum

Gray-bearded Member
Original Poster
claudiusx":hg561540 said:
That one linked does have a reflector, but its downside (or upside depending on how you look at it) is it's a remote mounted ballast - the ballast isnt self contained in the fixture itself.

I thought I linked you the 36inch model
No foul. I'll find it. Remote ballast is no problem--even preferred if better than self-contained--since everything is concealed in that top 8" compartment.
 

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