Abstract: A synergistic microbicidal composition having two components. The first component is a nonionic surfactant with structure: R1O(CH2CH(CH3)O)5(CH2CH2O)9H, where R1 is a C8 alkyl group. The second component is 2-methyl-4-isothiazolin-3-one. The weight ratio of the nonionic surfactant to 2-methyl-4-isothiazolin-3-one is from 1:0.005 to 1:1.3714.

Abstract: A synergistic microbicidal composition having two components. The first component is a nonionic surfactant with structure: R1O(CH2CH(CH3)O)5(CH2CH2O)9H, where R1 is a C8 alkyl group. The second component is 2-decylthioethylamine The weight ratio of the nonionic surfactant to 2-decylthioethylamine is from 1:0.004 to 1:0.0137 or 1:0.016 to 1:0.4571.

Abstract: A synergistic microbicidal composition having two components. The first component is a nonionic surfactant with structure: R2O(CH2CH(CH3)O)3(CH2CH2O)5H, where R2 is a mixture of C8-C14 linear alkyl groups. The second component is 2-bromo-2-nitropropane-1,3-diol. The weight ratio of the nonionic surfactant to 2-bromo-2-nitropropane-1,3-diol is from 1:0.08 to 1:0.12 or 1:0.2 to 1:1.8286.

Abstract: A synergistic microbicidal composition having two components. The first component is a nonionic surfactant with structure: R1O(CH2CH(CH3)O)5(CH2CH2O)9H, where R1 is a C8 alkyl group. The second component is cis-1-(3-chloroallyl)-3,5,7-triaza-1-azoniaadamantane chloride. The weight ratio of the nonionic surfactant to cis-1-(3-chloroallyl)-3,5,7-triaza-1-azoniaadamantane chloride is from 1:0.2 to 1:1.1429.

Abstract: An aqueous microbicidal composition having two components. The first component is a nonionic surfactant with structure: R1O(CH2CH(CH3)O)5(CH2CH2O)9H, where R1 is a C8 alkyl group. The second component is phenoxyethanol. The weight ratio of the nonionic surfactant to phenoxyethanol is from 1:1 to 1:18.2766.

Abstract: An aqueous microbicidal composition having two components. The first component is a nonionic surfactant with structure: R2O(CH2CH(CH3)O)3(CH2CH2O)5H, where R2 is a mixture of C8-C14 linear alkyl groups. The second component is a benzoate or sorbate salt. The weight ratio of the nonionic surfactant to the benzoate or sorbate salt is from 1:0.12 to 1:109.7646.

Abstract: An aqueous microbicidal composition having two components. The first component is 0.5-5 wt % of a mixture of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one. The second component is 1-10 wt % of a nonionic surfactant comprising a C6-C12 alkyl group, an average of 3-7 moles polymerized units of propylene oxide and an average of 5-12 moles polymerized units of ethylene oxide.

Abstract: An aqueous microbicidal composition having two components. The first component is 0.5-5 wt % of a mixture of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one. The second component is 1-10 wt % of a nonionic surfactant comprising a C6-C12 alkyl group, an average of 3-7 moles polymerized units of propylene oxide and an average of 5-12 moles polymerized units of ethylene oxide.

Abstract: Systems and methods for monitoring biofilm growth are provided. A method comprises supporting at least one coupon in a water reservoir, wherein the water reservoir feeds water into a tower interior, removing the at least one coupon from the water reservoir, and measuring a level of biofilm growth on the at least one coupon. The level of biofilm growth on the at least one coupon is predictive of a level of biofilm growth within the tower interior. Providing an indicator of predictive biofilm growth may allow measures to be taken to prevent biofilm growth in other sectors or areas of the tower.