i've used water, successfully, I've used an empty foiled pan, successfully, and I have a clay saucer for some reason foiled in the water pan and all of the above with no guru, Lately. the saucer may help the steadiness, but I personnally am starting to think its just sitting in there doin nothing, hehe. I run with all vents closed but one and adjust with that one, it may be wrong, or maybe right but it sure works and tastes good. just remember with no water in pan (i've noticed the following) your temp will be more sensitive in that, I try not to let it get away from me (go higher then desired at startup) and it was helpfull to me to have the thermometer alarm of somesort in case sun came around the corner or whatever... they don't take long to respond w/ no water or thermal mass (but i'm only used to water having the biggest effect, i've never used sand etc. seems funny to me) mostly this is why I only work the easiest to reach vent, and just the one, with no water it doesn't take much throttle to get er hot. top vent wide open and enjoy, im confident you'll be happy, and if not I gaurantee from this site you can get it fixed just like you like it. BUT you def. can use water at our elevations, I used to a lot, it burns more fuel but...... to me not to bad, just takes more to keep her hot. whatever you decide will work, when water was used, I used AlL the bottom vents as well. I was currently having problems with my guru (long story, but I posted about it) or i'de love to tell you the benifits. Seems to me everyone is tickled with it holding within 5 degrees easy as long as you have fuel... which means basicly you could seriously hold a specific temp. for like....hours and hours.. maybe 22 even, or so. All I can tell you is mine W/O a guru, is easy to hold within 10 degrees for the same amount of time. I deal with heat surges once in a while, and drops once in a while, but all minor. ex: for a 6 or 8 hour cook, i'll bring myself to adjust 3-7 times, depending on pickiness. apperently the guru, none times, for most, except me, lol. I wanted a guru, for all night briskits, and pork butts... etc. you pry know all of the above so i'll shut up! take it easy. -Dan