keeping up ambient temps in plastic tub?

hey guys, i was just wondering how to keep up my ambient temps and the temp of the cool side in a plastic tub. i have my four month old bp in a plastic tub (i only have one snake, so just a single one, no snake rack) with a heat pad on one side set to 90 but am having trouble keeping up the cool side. currently i have just been heating up the whole room to get the cool side around 77-80 and it isn’t that hard because it is a pretty small room but this has lead to a lot of fluctuations in temperature and just being not as steady and reliable as i would like it to be. i know temps fluctuate in the wild i just don’t want this to be in any way damaging to my bp. i know people use heat lamps and ceramic heat emitters but i don’t how how to use those with my plastic tub setup without melting everything. i’ve also heard of putting another heat pad on the cool side but i don’t know how well that would work to raise ambient temps and also his hide on that side has a bottom to it so i don’t really see the point but correct me if i’m wrong. i’m open to any ideas.

You don't use a heat lamp with a plastic tub, that's asking for trouble, you use a second heat pad and a second thermostat if you feel that the temps need to be higher, however your temps on the cool side are fine.

I agree that your temps are fine where they are. I have a few critters in tubs as well. I'll sometimes add a heater in the room to boost my ambient temps. My temps will drop into the lower 70s during the winter months. I don't think it's a big deal at all as long as the snakes have access to a hot spot at least during the day. I know some breeders and keepers that cut off the heat at night but I haven't done that yet.