I was thinking of getting a red bulb just to have a little visibility in the viv. What's a good wattage that will give good visibility without making it too hot for my leo?
It all depends on the size of the viv, I'm guessing you're using it in conjunction with a UHT, so if your temps are good with the UHT you have now, you want the lowest you can get.
The 15 watt red bulbs made by Zoo Med are awesome, quite bright, but not too bright and don't get too hot. They are nice for viewing without heating up the tank too much. I don't think you want more wattage than that for leos. Not sure why people use such intense lighting for these critters. One 15 watter throws off a lot of light. Two of them is a lot really.
Screw going to a pet shop and getting them. You can go buy them at home depot or lowes for a 1/3 of the price, theres not a big differance besides price.
if it's just for viewing as you stated- then I also suggest getting the LOWEST watt you can find- esp if it's a red heat bulb. BUT I'd recommend getting just a tinted red light (not heated) they will save energy and not over heat your leo or take out humidity,etc.. They're also much cheaper and work just the same, that's what we did. You can also find them just about anywhere, and I googled them not too long ago and found some of both kinds online very cheap too. DEF go w/ a low watt red tinted bulb though, if your gecko's heat is already good.
I just buy the party ones from wally world. A lot cheaper then the ones advertised just for reptiles. It serves exactly the same purpose. I get the 15 watt and I don't have to worry about it heating my tank up too much.