Frequently the wood heated hot tubs have NO pump or filter, and they try to get by by changing the water once a week (doesn't work too well)...but it makes for a VERY inexpensive hot tub (tub, bench and wood heater is all you need). Most of the wood heated tub we sell, we really try to talk people into at least a small filtration system...but there's always a few hard core purists, and people that are totally off-grid.
