personally Terry, i'd use this
http://www.plymouthdiscus.co.uk/prod...17c1eda9148011
I've used it before for internal parasite symptoms, i generally dose my community tank every 3-6 months with stuff routine actually, sooner if i notice any fish going "skinny"
Never had any fish deaths with it, even with up x10 dose being used.
It also kills snails, i can testify to this, you might need to add a second dose a few days or a week later to really hammer the snail population
I'd view it as a safer alternative than the anti-snail meds anyway (which are likely to contain copper)
It doesn't kill the snails overnight, seems to take a few days, up to a week maybe
The more you order of this stuff the cheaper it is, check it out.