These two are the same. สารกันเสีย Phenoxyethanol SA (Optiphen Plus) can be changed to Mild Preserved Eco 1% Yes. Yes, it's more gentle + can claim that "no objects กันเสีย " because all of them are completely soluble in water. Mixing method is convenient by pouring each substance into Pitera and then stir until dissolved. Then pour the next substance until it's complete.