For tougher algae species, I might suggest a combination of GREENCLEAN Liquid and HYDROTHOL 191 (3:1 to 6:1 ratios, respectively). These two products compliment each other with different modes-of-action.
Also, never tank-mix CUTRINE (or any form of copper) with GREENCLEAN. The exothermic reaction of an oxidizer combined with a heavy metal; though entertaining to watch, isn't overly "friendly" on application equipment - and certainly isn't desirable from a performance standpoint.
I've been impressed by GREENCLEAN LIQUID's effectiveness. However, its downside involves the need to dilute it with water before application in order to provide enough volume for thorough coverage and penetration of matted FA-growth (or for subsurface injections). Since the oxidation-process is "triggered" as soon as the product contacts water, tank-mixing GC Liquid with water requires that it be applied relatively quickly - before the reaction "fizzles out".
The device shown below is a newly developed 12v sprayer (patent pending) that overcomes this dilemma by sourcing water-diluent from over the boat's transom and "live-injecting" the product (ie. GREENCLEAN Liquid alone, or in combination with HYDROTHOL 191) from a concentrate-reservoir immediately before the diluted mixture exits the spray-gun. The volume produced by this injection-system benefits algae-mat penetration while avoiding the decline in GREENCLEAN-activity that occurs if it is pre-mixed with water in a spray-tank.

BTW: Cygnet isn't the only source for these and many other aquatic products whistle


Kelly Duffie
Cypress, TX