Ryan, I'm suprised. You once stated that you were a strong proponent of providing full spectrum lighting to diurnal species, inluding box turtles.
I had a conversation this past weekend on this very topic with two highly experienced and successful turtle keepers. Neither of them use full spectrum lighting on their young box turtles. Like Woodnative and RMB (based upon photos of their beautiful and healthy young turtles), my acquaintances' turtles are healthy, smooth, and pretty.
My opinion has recently changed on the subject. I used to think that it was absolutely a necessity. Isn't that what science is? Data, interpret, practical application, new data, reinterpret, new application. I had seen SO MANY young box turtles with deformities. Even many pictures posted on here of supposedly healthy young turtles show "odd" growth. It seems to me that the vast majority of captive raised box turtles develop growth problems. I chose to recommend all that people could possibly do. If there is a deficiency in the diet, which is undoubtedly common in captive turtles, full spectrum lighting may fill in the "calcium gap". If, like you, people provide a vast and varied diet including wild caught creatures, they may not need full spectrum lighting. I think that is clear.
For me, it has been very clear that full spectrum lighting has helped my hatchlings. I've been doing this for more than 20 years, and I noticed a vast improvement when I purchased my first ESU Daylight. My hatchlings are more active, eat better, and even bask under the lights (in the Superman pose just like a Slider).
I can't duplicate nature. Nobody knows what hatchling box turtles do in the wild...they're almost impossible to study. I've tried. Are they usually found hidden?...yes. Have I found them out and about?...yes. I'm only using the tools available in order to raise the healthiest hatchlings. No doubt, nature is our guide, but we shouldn't fool ourselves into thinking that we are duplicating nature. I am not saying that this is what you think, I am only outlining my line of thinking.
I, and many others, have had the benefit of seeing how the addition of full spectrum lighting has changed our results. I typically raise about three dozen hatchlings comprised of various box turtle species every year. Most I only keep until they are about 3 inches, but I have kept many beyond that over the years. Could it be that you are providing something else that we aren't?...absolutely! That may be why you don't need full spectrum lighting.
Some people need it. Others can probably do without it. I went without it for 15 years. It has so improved my results that I now think it is well worth it. Remember, there is a difference between what you need to provide and what you should provide. Each keeper must make those judgements. For some, it may not be a waste. Personally, it has been the best addition to my hobby...hands down.
I don't place hatchlings outdoors to sun. It seems stressful for them, it is too time consuming for me, there's a risk of overheating, and I've had a few hatchlings get picked off by Blue Jays. If a keeper can do it...great!
I respect your position. I hope you can respect mine also. You have clearly had good results without full spectrum lighting. I have clearly seen an improvement since I added it. I will continue to recommend it for novice keepers. Redundancy is not a bad thing, especially when a keeper is first starting out. Even slight deficiencies may lead to negative results.
One other problem...at what point to you provide full spectrum lighting?...never? I keep my turtles indoors until they are about 3 inches. Others keep their turtles indoors for their entire lives. Hatchlings hide most of the time, but a 3 incher is active at the surface quite a bit.
For those concerned about energy usage, there are compact flourescent UVA/UVB bulbs now available for a relatively small price.
I look forward to reading your opinions of this post. Please know that I only mean to share my opinion, and not attack others' opinions...well, unless they are entirely uninformed and obnoxious.