I got a reptile basics rhp. I used it on a glass tank before I built the viv, and I think you could use it on a tub too with a little work - basically, put a piece of wood over the lid so the screws have something to go into. You'll need a taller tub than you otherwise might because the panel will take up some head room. I think RHP's are a great way to heat anytime, but especially when you have low ambient temperature in the room. The reason is that for the same wattage, they spread the heat over a larger area and therefore nothing needs to get to as high a temperature in one place. And since the panel is entirely inside the enclosure, it loses less heat to the room than a lamp from above, whether it's a che or incandescent. It's initially more expensive, but once you have it you're good for a long time.