Habitat - Indoor :: MVB Bulb

[marisa]

N4784N.... to answer your question, no, you can't use a dimmer (rheostat) with a mercury vapor bulb. You can use a timer, but they're not supposed to be used with a dimmer.

A 100-watt bulb though 1/2 inch hardware cloth should produce enough UVB rays for your turtle. And your turtle is also getting some Vit D from his diet.

Personally, rather than getting too much UVB from a mercury vapor bulb, depending on its placement, I'd be more concerned about damage to the eyes. The sun peaks at noon, but it's much stronger than the light from (most) UVB bulbs, and the rays bounce off objects, which means, a turtle in the wild can conceivably still get a fair amount of the rays even in the shade.

[Muirner]

I read that most reptiles eyes are positioned in such a way that they do not suffer from glare. While i completly understand what your saying marisa, having that light on for 8 hours a day at some point there has to be some glare. Maybe the light could be on a timer just to be on at light noon-2pm??

[Kallistos]

Occasionally they'll look up ,but after a few minutes their head droops. Hopefully I can pick up the 100 watt flood over a Christmas sale. Right now it's $50 w/o shipping and then about $15 for a lamp, ouch!

I agree, with a MVB I won't keep it on too often, I'll try to mimick the sun a little better. Maybe 10-4, so both of them get a turn because they don't like basking together.

Thanks for all the replies, I bet this will be a very helpful topic for others like me.

[Muirner]

RES - that is the T-REX bulb that the link was to on the first page? Now that is a UVA/UVB and heat lamp in one? Right?

[Kallistos]

Yes it's the T-Rex active UV heat. It's a Mercury Vapor Bulb that provides UVA/UVB and heat. The other major brand of MVB is Powersun by Zoo-Med.

******BEWARE******

The link I provided is to the outdated T-Rex website which has incorrect safety instructions. Look at my later post for the edited minimum distance for the different wattages of the Active UV Heat MVB.

[SpotsMama]

RESowner34, I'm pretty sure you won't get the heat you need to motivate basking if the 100 watt MVB is 18" from the basking turtle. That's the same bulb I use and I measured the temperature at about 16" and it was 88 degrees - barely warm enough. You'd better measure the temperature if you set yours at 18" and make sure it's high enough for basking.

By the way, I didn't think Spot was basking enough so I lowed the bulb a couple of inches and now he's basking a lot more - 3 or 4 hours a day. He loves the extra heat. The distance now about 13" between the MVB surface and the basking turtle back.

I'm thinking when the 100 watt bulb expires if trying a 160 watt bulb and keeping it further away from the turtle - maybe 18" would work with a 160 watt bulb. I worry about the danger from a splash with the bulb so close as it is now.

[marisa]

I just installed a new 160-watt mercury vapor bulb over my RES's tank on 11/17. It's currently on from about 8:30 am to 7:30 pm (I'm going to shorten the time further in Dec.) and is about 18 inches from my basking RES. He had a 100-watt one when he was in a smaller tank, and it was a bit closer than the one he has now. He doesn't really splash---I splash more when I'm dumping water in his tank. I think the bulb can be on for more than two hours a day (12:00 - 2:00 pm). I don't know about your turtles, but my turtle doesn't always bask when the light's on. Suppose yours don't want to bask at that time or want to bask more?

Mercury vapor bulbs are not the sun, although they can come close, at least for a while, until they need to be replaced. They will lose UVB output over time, even though they still give off heat. The UVB rays can be intensified to some extent depending on what they're screwed into, and distance will cut the strength of the UVB output as well as the heat.

[Kallistos]

So you're able to obtain basking temperature from just 18 inches away? hmm....I think I may change my mind, either way I know I won't be dissapointed and my turtles won't be either. I'll ask my dad if we can construct something to hold it 18 inches away. How did you do it Marisa?

[N4784N R4613]

N4784N.... to answer your question, no, you can't use a dimmer (rheostat) with a mercury vapor bulb. You can use a timer, but they're not supposed to be used with a dimmer.

A 100-watt bulb though 1/2 inch hardware cloth should produce enough UVB rays for your turtle. And your turtle is also getting some Vit D from his diet.

Personally, rather than getting too much UVB from a mercury vapor bulb, depending on its placement, I'd be more concerned about damage to the eyes. The sun peaks at noon, but it's much stronger than the light from (most) UVB bulbs, and the rays bounce off objects, which means, a turtle in the wild can conceivably still get a fair amount of the rays even in the shade.

OK, good to know, thanks. Right now I have the timer set from 9 to 9, and the bulb is 30" away from the dock(Yes, I know 30" is allot, but thats what keeps it right at 88F to 90F ) . Do you think I should lessen the time that the bulb is on for? If so, should I use a a weaker bulb when the MVB is off?

Thanks again,

Nathan Radle.

[Kallistos]

I thiank that starting it up at 9 A.M. is perfectly fine. You may want to have it end at around 5 or 6 o' clock so it imitates the sun a little more. Do you have just one turtle, if you have more than one, do they bask at the same time? You should take that into account too.

[Kallistos]

I was thinking of buying that Zoo med Reptilamp stand. Then I'd put it directly on the wire mesh, it's maximum height is 30", We'll see....

[Muirner]

So your lights come on at 9am?? The cycle i have imitates day light around here as much as possible.

Right now they come on at 6:30am and go off at about 5:30pm.

[marisa]

RESowner34, I'll check the distance again just to make sure. I have a Zoo-Med stand (waiting to be used once again---it's been in mothballs for a while). I used the 100-watt T-Rex with it without any problems. What are you putting on the wire mesh---the bulb with the reflector? Why don't you just hang it from the stand (am I thinking of the same stand you are?)?

[Kallistos]

We're talking about the same stand I'm pretty sure. I'm saying I'll put the stand itself on the wire mesh, and I'll still hang the bulb from the stand. The zoo-med stand only extends up to 30" vertically. Maybe not on the wire mesh, but somehow attached to the tank cover.

[marisa]

These stands come in two sizes, the one for small tanks and the regular size one. I have the larger one. I'm not sure how high the larger one goes, maybe it is 30 inches (?). The thing with this stand, though, is that it has a plate/flat piece on the bottom that is to be put under the tank to keep it from tipping. The weight of the tank and water hold it securely in place. I'm not sure how you'd keep the light steady without putting the plate under something...When I was using it before, I had the plate under a 50-gallon Rubbermaid storage container and was using a 100-watt mercury vapor bulb.