Hi,
I bought an ExoTerra 60x45x60 vivarium - I made a "great stuff"-type foam background, drainage layer with clay balls and a small part for a pool. A small "stream" is going into the pool and a submersed pump running it. In addition, we have the Monsoon 400 by ExoTerra for misting.
The vivarium is for red-eye tree frogs.

With regard to heating, I put a small 25W heater into the water (under the drainage layer) and set it to 28C. On top I have the ExoTerra compact top with 2x25W light bulbs (Natural light). The compact top could take 3x25W, but that would seem very very bright to me - particularly for the red eyes, which sleep during the day and I'm guessing they are not too keen on heavy light. The room around the vivarium is approx. 22C.

With this setting, I cannot get temperature inside the vivarium to raise much above the room temperature outside - around 21-22C. Water temperature with the small heater is 27-28C but I guess with everything else in the vivarium, the water cannot heat up the rest of the space and the mister probably cools it down continuously as well. I understand that red eyes like between 27 ant 28 to keep them happy, so this is far too cold.

With all that said, what kind of heating solution would you recommend I should do? ExoTerra sells things like heating mats to be put underneath the vivarium, but I read on the forums that they don't do much good... with all the ground layers in the vivarium, that the mat does not give much effect?

Any suggestion would be very welcome.