Our pool heater was connected to a large (120 gallon?) propane tank, but we only used it a few times a season (just for heating the attached spa, not for the big pool) and couldn't justify the tank rental fees.

I was wondering if I could adapt the small propane tanks (the kind you get at Home Depot et al) for occasional heater usage. Any pointers to technical issues I might need to research (pressure levels, regulator, connectors) would be appreciated.