Hi all I was wondering if any skiing Funsters had used one of these successfully to stop an underslung GREY tank freezing. The website quotes a current draw of 2.5 amps which is fine for us because we are well endowed in the battery department! The website also quotes that this element will also prevent the freezing of 45 litres of water, in an uninsulated tank, at -25, subject to tank shape. Well, I intend to insulate our tank and bearing in mind nearly all waste water discharges are warm to start with, do CAK's claims stack up? If any Funsters have any real time experience of these units in Alpine conditions, I would be grateful for your collective opinions. As mentioned previously, the current draw isn't an issue for us, even off grid. Thanks in advance!