I use my pool vac hose with the vac head on it to drain and vacuum the bottom of the spa. First I place the hose over an active jet and as the tub siphons ,I turn off the tub,slip the vac head on and drain the tub in about 30 minutes as I vacuum the bottom .All but an inch or so of water will drain,so a bailer or shop vac is needed .Works great for me.....bobhol