i set my viv up last night i have coco husk on the side with the heat mat and moss on the other my heat mat is 11x7" 11w the temp doesnt go above 20c what would be the best way to raise the temp.

it is an exo terra viv 60x45x60cm with the fake back ground still in place would it be better to use a heat mat on the side/back or a heat lamp any ideas would be good.

i am getting my frogs next weekend and will buy what i need of ebay so fast responces will be appriciated thanks