I prefer Airmax Nature's Blue Pond Dye Packets, used to use the liquid, but the powder works as good or better. I especially use it in winter, when water clarity would otherwise be crystal clear.
It's a cold dark place down there from fall to spring, which makes it very hard for the weed biomass to hang on, and it gives fish a fighting chance when the otters come visit.
In spring, as the algae bloom starts to do the job of preventing light reach bottom, I use less of it.
