Having handled SofTub in the past, and witnessing how consumers care for them, I would strongly recommend "SofTub chemicals" ONLY. They are buffered for the vinyl liner. Regular chemicals can and will do damage to the vinyl skin, which can be replaced by a "new" vinyl skin for close to a $1,000. The cost of potential damage far exceeds the savings of any "sale priced" chemicals that could do some serious damage to your tub.