i dont like snails..

Had a little bit of a scare a couple hours ago.. one of my snails got onto the sensor of my jbj ato and turned the pump on. I was home but I was re-scaping my other pets tank (bearded dragon). So I came out to the living room and saw my 20long filled all the way up just about to over flow. Luckily the timer on the jbj shut off the pump after 3 min. So I sucked water out and checked salinity. Normally at .026 and was .024. Little change in a short time but everything looks good and not angry. Mixed up a half gallon of higher consentrated saltwater and am now still slowly raising salinity. Would like to get rid of the snails but I think they keep the tank a lot cleaner. Hopefully won't happen again. I was lucky