Equipment Review and Discussion :: Powersun mercury vapour light

[Terrapin UK]

Actually, to go with the new tank I have been considering a 100W Powersun mercury vapour light. Has anyone got any experience of them? At 50ÁW/cm2, compared to 10ÁW/cm2 from the Reptisun 5.0, they sound good!

I've heard of there being problems in small tanks, what with too much heat being produced, but I can't see this being a problem with my 119 gallon tank? (Plus, seeing as how it is winter in the UK, my poor terrapins won't be getting UVB from anywhere else!!!)

[steve]

(I made this into another topic... it maybe useful later on)

Anyway, I haven't used it, but mercury vapour bulbs do have a fairly good reputation. They also last longer than UVB lights (though I do not know how long they last, it will vary depending on the manufacturer's specs) and they also produce more UVB (again, it will vary). I take my RES out often during the summer, so I only use a new UVB bulb during the fall.

[Terrapin UK]

Cheers Steve!

As I say, the UK is pretty useless for sun, so I need a bulb all year round. Having the 100W Power Sun would also save having lots of different lights and wires hanging everywhere. It is claimed to last 10,000 hours, which at 12 hours a day puts its lifespan at just over 2 years. I assume this means the UVB lasts 2 years, but I'm not entirely sure.

I think I'll try one and see. If it doesn't produce enough heat I've still got a couple of spare basking lights and a clip on lamp as a back up.

I'll report back with my findings!

[marisa]

Some people love this bulb, some do not. A number of people have complained about its having a short working life (I have never read of anyone who has used the same bulb for two years, so maybe your being a little optimistic here. To my knowledge, it's replaced after a year.

I've never used a Powersun, but have used a competitor, T-Rex's Active UVHeat bulb and I liked it. T-Rex has actually started making it's bulb with a newer technology, and reports about it have been positive.

These bulbs (MVBs) can overheat, and if yours suddenly goes out and won't go right back on, turn it off and wait 10 minutes for it to cool. I used to do this with the Active UVHeat one, and it would go back on again. The Powersun should as well, unless there's something wrong with it. Good luck with it.

[Terrapin UK]

Cheers Marissa.

As I say, I'll give it a go and see. I got a UVB meter for my birthday last week, (I'm a quater of a century now - oh no!) so I will test it to see what its output is. I wonder if I can return it if the output doesn't reach the claimed 50ÁW/cm2!!

If it turns out to be rubbish, or my terrapins don't like it, I'll get my flourescent bulb stuff back out, and put it down as a slightly expensive waste of time!

[Terrapin UK]

I should add that this site has some pretty useful info on different lights and their UVB output:

http://www.uvguide.co.uk/usinguvmeter.htm

[marisa]

A belated happy birthday! What brand of UVB meter did you get?

[Terrapin UK]

It's a Solarmeter 6.2, which I believe is made in the USA. It was much cheaper than the British made stuff on sale here!

[marisa]

Yes, I've seen this model recommended by a number of people (someday I hope to be able to get one as well). They're about $179.00 here, I believe. One person said that what surprised her most when she started testing with one was how many bulbs weren't emitting what they should have been according to the mfgr.

One thing I've wondered about these meters, though, is how does a person know that they're accurate?

[Terrapin UK]

That's a very good question!

I know there are sites that list the amount of UV radiation certain places in the world get, so you could roughly check it that way. I believe on a clear summers day the UK gets about 50ÁW/cm2. Other than that though, I guess you just have to trust it!!!

[Terrapin UK]

Me again!

Well, I've tested the mercury vapour bulb, and it produces the advertised 50ÁW/cm2 from a distance of 18" above the basking spot.

So, I just thought I'd check - does anyone know what levels of UVB are safe for terrapins? I don't want them getting too much.

Cheers,

Liam.

[Terrapin UK]

Surprisingly, it doesn't give off that much heat. I put a thermometer under the bulb for 1 hour last night, and it only got up to just over 70 degrees. I have had to install a 60W basking light to give more heat! (Although I guess if the bulb was in an enclosure it would be hotter. My basking area is to the side of the tank, so more heat can escape).

[reptilegrrl]

I think these are far superior to the flourescent UV lamps. I definitely noticed more activity and greater appetite when using them with my box turtles.

One thing about these is that the light is very intense, so they require a complicated setup. When my turtles were indoors, I had the lights set up on timers. I had the merc vapor lamp as well as an incandescent heat lamp, all hanging above the turtle pen. The timers set the incandescent lamp to come on at "sunrise", then at about 10 am it would turn off as the merc vapor lamp turned on. At one or two pm, the merc vapor lamp would turn off, and the incandescent lamp would come back on.

The merc vapor lamps are so intense that a full 10 hours or so of exposure is not only unnecessary, but could be dangerous. This is actually in the literature that comes with the lamps.

I found that 4 hours or so of merc vapor lamp was sufficient to keep my turtles healthy and active.

[reptilegrrl]

Some people love this bulb, some do not. A number of people have complained about its having a short working life (I have never read of anyone who has used the same bulb for two years, so maybe your being a little optimistic here. To my knowledge, it's replaced after a year.

I have used both the T-Rex and the Powersun. Neither one lasted a full year! The merc vapor portion of the T-Rex lamp burned out after about 9 months of use, and the entire POwersun burned out after about 3 months of use. ZooMed was bitchy about giving me a new one, so I won't buy theirs again. If I must buy another, I will try the Big Apple house brand.

[marisa]

Yes, I've read that there can be problems from too much UVB as well. With the stronger lights being close to the turt there has been concern over eye damage.

Reptilegrrl, I don't think the set-up for a mercury vapor bulb has to be complicated, just larger (the bulbs are not recommended for smaller enclosures because of the large amount of heat they give off). I use a mvb in my largest enclosure (110-gallon stock tank), and the mvb bulb hangs 18 inches above the basking area (the distance recommended by the Mfgr). At the opposite end to give the tank added light, is an energy-saving spiral light in a regular floor fixture. The spiral light comes on about 30 minutes before the mvb, kind of like the sunrise you described. In the evening, the process is reversed to lessen the light more gradually.

I've never used the Powersun, mostly because of the complaints I read about it not lasting. My first T-Rex bulb lasted two months, and had to be returned to the mfgr for a replacement (which they did promptly and some "extras" to thank me for my patience). The second one lasted for a full year and was still working when it was replaced (I may use it again for added lighting in the future).

If you're talking about Big Apple's Capture the Sun bulb, I was talked out of trying one of these because of how quickly I repeatedly read they stopped working. I would recommend instead the Mega-Ray. I've been using one since June, and it's been fabulous (knock on wood). During the summer it wasn't used much because my RES was out in the sun a lot, but since he's been inside and the bulb is in use every day (11-12 hours), it's been working just fine. In testing these bulbs have been shown to be superior in terms of the amount of UVB light they provide and their "burn" rate (the rate at which UVB strength is lost) is lower than other brands. You might also consider the T-Rex again. I read that the bulb has been redesigned and now incorporates the same technology that the Mega Ray does (I think the same company makes both).