SK7 treatment powder from Bio-Systems International is available in a variety of packaging options, including a klick box and outhouse, each providing 12 monthly applications for septic tanks or long-term portable restroom holding tank use. Drop one water-soluble pouch into a restroom holding tank monthly to provide a premeasured dose of beneficial bacteria. Packets are individually shrink-wrapped, ensuring the product stays clean until used. 800/232-2847; www.biobugs.com.