Lighting getting hotter?

[Mavrick813]

Ok everyone, here's a situation that is confusing me. As you know I have Toothless in a custom enclosure. This is a convert from a Sauder Workstation cabinet. The sides are that compressed laminated wood material. the back is that Tack On Cardboard stuff. The front is 1/4" Plexi. On the left side I drilled a 3" hole and sealed it with Screen then put a Metal Fan guard over it.

Lighting includes, 1x Reptisun 10.0 24", 1x GE EcoLux 3500K 17W office bulb, 1x Reptisun 55W Basking Spotlight. These 3 lights are on from 7:30am to 10:30 PM. Temps on Toothless basking rock would climb to 105-106*F. The cool side by the vent would be around 72*F. Toothless has made his branch the most popular location excepting right after he eats. I check the temps every time I open the enclosure with my PE-II temp gun. My digital probe always reads around 98*F just above the branch that Toothless tends to stay on.

For night time I have a 60W CHE that brings the basking rock surface temp to about 96*F and the cool side of the tank to about 71*F. I didn't like this so I went to Lowes and bought a couple of Inline dimmer switches. I dialed the CHE back and got the Surface temp of the basking rock down to 86*F all night long and the vent area drops to 69*F give or take.

OK, Temps have been solid for a couple of days and the ambient room temp is about 64*F at all times. Today I go in to give Toothless some ReptiWorms and it felt a little warmer. I check the basking rock and it's 119.7*F! I check the dimmer and it hasn't moved. I dialed it back some more and left the door of the enclosure open for 45 minutes. Get the basking spot down to 103.8*F and close the enclosure. I wait 45 more minutes and check the temps and the basking spot is back up to 117*F. I dial the Dimmer back some more and redo the process. At this point the basking light is at half power. And is now holding the temp of the basking spot at 105.4 the rest of the temps look good.

So my question is. Do the basking bulbs get stronger as they burn in? This bulb has been running about 14 hours a day for 1 week thus far.

Any ideas?

Mike

 

[Kajolic]

I've been following this thread since it was posted hoping to see some replies to its regard, but I think I will be able to shed some helpful advice the temperature battle.

I have two basking locations (one on a faux rock, and one on some driftwood) and an additional heating bulb for use if temperatures doesn't reach ~85°F on the cool side. From what I've contended with on Day 1 of having my Beardie in the Viv was the same battle with the dimmer switch on the faux rock basking spot (50-watt). I would dim it to cool it down to ~113°F and check in 20-30 minutes later, it would be up to ~120°F, repeat, check it, back up, repeat...*sigh*
I did not, at the time, have a dimmer on the second basking bulb (35-watt) as to it was at 109-112°F steady and the 3rd bulb (35-watt) for heat to achieve ~85°F on the cool side in the morning during these cooler days. (I'm in a two story town house, in the corner of a condominium unit with vacancies to either side of me, so no radiate heat from 3 sides of my computer room)
After placing a dimmer switch on these light this morning, I was able to reduce their output to achieve a proper heat gradient within the tank from basking area (~113°F (95°F surrounding ambiance temp)) to the cool side (~85°F) without having to make the many adjustment to the dimmers to maintain a proper basking temperature.

Basically, taking my best educated guess on the situation and keeping in mind you have a single heat source bulb, as the Viv is heated by said bulb, if you have the basking spot set at 105°F and the tank is being heated hotter by the bulbs radiant heat, the basking spot that was being kept at 105°F by a cooler ambiance earlier in the morning, is not a hotter ambiance, the basking spot will now be much warmer since it cannot be kept cool by the hotter ambiance. I hope I didn't make that too drawn out, and make to miss my point in what I think is going on.



I did want to note, on your GE EcoLux 3500K 17W...I have been reading a thread to the regard of these bulb (general lighting bulbs) (Reptisun 10.0, lethargy and closed eyes) They are saying it is recommended to use a 6500k, which I use the Naturesun from Zoo Med which is right at 6500k. Definitely check into that thread, if you have not already.

 

[Mavrick813]

Thanks for the reply! I'll definitely be reading that thread and I think you hit the nail on the head.

Mike