I know the rule is that the heatmat should cover a third of the viv.
I am trying to decide what size to get for the new viv stack. The internal dimensions of each viv are 35in x 20in.
A 17x11in mat doesnt cover at least a third, but if I get the 23x11in mat I would have to put it so that it covered over half of the back but none at the front (Does that make sense??). Ideally I could do with one 17x17in but can't seem to find any.
Ok, dunno if people will say this is wrong or not but it's what I do and have never had any problems.
I use a heat strip not mat and they are not very wide. They only cover around 1/4 of the bottom of the larger rubs I use. I know they say it should be a 1/3 but the way I see it is as long as there is enough warm area in the tank for the snake to stretch out on or coil up on to get warm then I don't see the problem with it being a bit under 1/3.