this review title is: optiphen plus not germall plus and the content is: optiphen is pretty good as a preservative and similar to germall but they are not the same if i order germall i want germall do a little research online they are mostly interchangeable but there are slight differences in the suggested ph range max temp and max usagfor exampleermall ingredients phenoxyethanol caprylyl glycol.there are other information for this review, one is this reviewer did purchase it and the other is 2 people think this review is helpful.