Solarmeters on a budget

Hello,

I've been concerned that my Powersun 100w UVB isn't as effective as it was when I first bought it 6 months ago. My beardie's coloring has been very dark the last week or so. I thought I read they get dark when they're trying to absorb light? She doesn't appear to be in early shed; as soon as I take her out her tank and hold her she returns to her normal light beige/brown color.

Her color being off led me to research UVB lighting here on the forum and I read Tracie and Frances' articles, and I'm interested in buying a solarmeter. However, the Solarmeter 6.2 is too pricey for my budget. Is there any other solarmeter out there that is as reliable for the budget conscience . . . meaning less the $75. If there isn't one that's fine, I don't want to waste my money on something cheap that is ineffective.

My set up:
*40 gallon breeder tank
*75w Sylvania Halogen flood light for basking, I try to keep it bet 102-105, it's on a lamp stand I can easily adjust the distance from the basking spot for the desired temp. The light is going through the mesh screen of my tank (bulb is brand new, about a week old).
*100w Powersun MVB (6 mos old) for UVB lighting placed in the center of the tank just to the right of basking light. Positioned approx 10-12 above her perch, usually positioned over an opening so the mesh screen is not blocking any UVB out.

Any help would be greatly appreciated.

Unfortunately I haven't found any effective alternatives for a Solarmeter. For what they are, they're actually pretty cheap. I know it's not in the budget for most folks though so the second best thing is to check out the charts that Frances has available in the UVB Meter Owners Group on Yahoo. According to the chart for your 100w bulb, at 12'' down you'll be getting around 3UVI which is decent. If you provide a branch that has a portion a few inches closer than that, it would provide a high UVB area but I'd opt for getting a more powerful bulb before going closer than 12''. Here is a copy of the test results for that bulb which may help you with positioning and estimating output at different distances https://www.dropbox.com/s/72red39zd97rhp9/ZooMedPowersun100W.pdf?dl=0

If there are reptile specialty shops in your area one may have a meter and could test your bulb for you. Unfortunately the less expensive meters are usually junk - the sensors detect UVA instead or just brightness.

Being Dark may be more of a heat thing than UV - if it's related at all.

Thank you, CooperDragon & Taterbug,

Im having trouble down loading the powersun doc but Im on my tablet. I'll give it a try on my computer tomorrow.

So the darkening of a beardies coloring is a heat adsorption indicator? Does it mean they're too hot? I know when Gizmo is cold her coloring appears normal or light. Just curious why she's been so dark looking? She hasnt gone through a shed in a long time but it doesnt resemble a shed.

Darkening in general means absorption. Lighter color will mean reflection (enough heat/UV or too much). It's not necessarily a bad thing when you see the skin darken, it just means she's trying to maximize the amount of heat/light she's getting. You'll often see them pancake out to increase surface area facing the light when they do this. My boys would darken and pancake out like that quite a bit when they were outside. Dundee used to pancake out, darken, and move around to keep his back to the sun as the sun moved like a little sundial. Keep your gradient (heat and UVB) in good shape and she'll move around and get what she needs.

Since the behavior is recent is everything else normal, activity level, poops and appetite still fine?

You could try replacing the UVB lamp. If it helps it helps, and if not you have a new one already when it's time to change. Is it possiblely the new basking bulb is it different, or makes a noise or flickers?

It could be low heat, if your enclosure allows you can try offering a warmer high temp, just need to make sure you can offer a moderate temp as well.

It can also just be a mood thing, such as being crabby at being in the cage.

Melanin reduces UV absorption by a small amount. However, the heat benefit of dark colors is significant - they use it to their advantage to warm up more effectively.