the problem with in ground pools is maintaining temp, where as above ground pools can stay at room temp, i have 4000 litr pond in the ground and it takes 3 300 watt heaters 24/7 to maintain 22cel. the below groud pool heaters are very heavy power users put this with all your pumps your bill goes thru the roofComatose;5049576; said:Has anyone done/considered doing an outdoor/inground pool (maybe inside a greenhouse) setup? This is my dream (which is sadly still a bit far off).