Sorry for bumping this thread, but I am wondering why the carpet in my fish tank was sopping bloody wet in the "height" of summer (when I had the hardback off and wanted to stop people stealing my wallet, camera, etc ... all of which got very wet), and yet is now (after persistent downpours in East Anglia for the past two months) dry as the proverbial ... erm ... very dry thing! Would suggest it's condensation, no? But there was a hell of a lot of it!