Vince, There should be recommended mixing rates on the cutrine bottle. Yes it is 1 gal per acre for depths up to either .6 or 1.2 ft. Everything you need to know about rates is supposed to be on the label. My understanding is that the 1 gal per acre is to ensure that the chemical is not diluted out before it can be effective. I think cutrine is best with a 24 hour contact time. Spray the floating mats and around the shallow areas in the depths recommended for the application rates. Direct contact with the algae is best but with the liquid it will disperse in the water column and kill a majority of the submergent algae in the shallows. I think cutrine actively lasts in the pond for about 2 weeks.
Lee- a stronger batch is not the answer. Keeping algae down with a single treatment of cutrine for 6-7 weeks is pretty good. The recommended rates ensure safety for the environment and fish and they are effective. The regrowth of algae doesn't neccesarily mean that you didn't most of it the first time. What it does mean is that you have a nutrient rich pond with the proper ingredients for healthy algae growth. If your algae is growing back within a month after treatment you may want to look at how excess nutrients are entering your pond(i.e. animal waste, lawn fertilizer, farm runoff etc.) and slow down the nutrient flow as opposed to adding more chemicals.
