I recently bought a forclosure with an in-ground fiberglass spa separate from the pool with it's own pump/filter system. It was covered, full of water, and had not been turned on in probably 2 years (green scum on top but didn't really look too bad). I drained and refilled it, had the filter cartridge checked (it's a large pressure filter like a pool), had the system checked, and with a few minor repairs it's up and running. Now I want to disinfect it. All of the disinfection processes I've found involve draining the tub 2-3 times. Two issues - my area has severe water restrictions, and I'm on septic so there's nowhere to drain super-chlorinated water. I'm looking for a solution where another draining is not required. Also, I have ordered a new cover. Thanks!
