BioGuard® Back Up 2 Algaecide – 1 Qt.
Prevent algae before it starts with BioGuard® Back Up 2, the most powerful algae preventative in the BioGuard® lineup. Designed to be your pool’s first line of defense, this non-staining, non-foaming formula is safe for all pool types and won’t affect your water’s pH. Its effectiveness increases as water temperatures rise—exactly when you need it most.

Thanks to a special surfactant, Back Up 2 works deep into tiny cracks and crevices where algae love to hide, keeping your water crystal clear and swim-ready. Plus, it’s stable in sunlight and won’t evaporate, giving you consistent protection day after day.