Ef Chlor (NaDCC) &ndash; Portable Water Purification Tablets - BULK PACK OF 10 STRIPS [100 TABLETS] - Each Tablet Purifies 6.6 GALLONS NaDCC 167mg tablets in foil strip of ten tablets. Each tablet purifies 6.6 gallons. Used by disaster relief agencies world-wide. effervescent, disolves in minutes. Effective against virtually all bacteria and viruses.