a boiler pump was used to move the fluid with a thermos static switch to turn it off and on. both can be had at menards don't know if they have them down there its like home depot. concrete here in Michigan is 4" thick for a standard slab, you grade your dirt 4 " below your final concrete level, so you can slope your grade to the front doors in a barn or to a drain in a basement. don't forget to allow for the thickness of the foam insulation under the tubes. so 1" foam would be 5" below your final level. I know you need to fasten the stuff down pretty good I've heard concrete guys saying it like to float in wet concrete.