Black ALL DAY

So my beardies basking bulb went out and I got a new one, the old one kept his viv at 100 degrees (he's still a juvie), but this new one only keeps it at 80. Ever since I've changed bulbs he stays black all day. He's NEVER done that while basking before. Is he okay?? Should I look for a new bulb??

Hi. How are you taking the temps? When they are dark that means he's trying to absorb more heat.

Need much more information and details on your beardie's setup and your husbandry otherwise we can't even hazard a guess.

Here's my Cheat Sheet :
viewtopic.php?f=6&t=234738&p=1806050#p1806050

If you work through it methodically , the chances are their are likely a lot of issues that need to be tweeked or changed and they will pop right out at you, if you can give very detailed answers we will then be in a position to offer help. Is impossible to help you if you don't provide thorough details .

I think your issue is he's too cold.
If you are using a dial type thermometer , these are uselessly inaccurate and you really don't know what the temperature is , I suggest getting some of these (at least) : http://www.ebay.com.au/itm/Aquarium-LCD-Electronic-Digital-Thermometer-Fish-Tank-Water-Detector-Practica-BU/252762165947?_trksid=p2385738.c100677.m4598&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D20160908110712%26meid%3D6ac464a2a1b24339be32c744b2ff5cf9%26pid%3D100677%26rk%3D2%26rkt%3D15%26sd%3D201577608563 , I use a few per tank or rearing tub and they have proven very reliable , very durable and are good +/- 1 degCelsius , and the batteries in them last years.