DrTim’s Aquatics Re-Fresh for Reef Aquariums – 100% Natural Fish Tank Sanitizer & Revitalizer Conditioner Solution for Fresh, Crystal-Clear, Sparkling Water - Size 4 oz - Treats 240 galReef Safe Refresh for Aquariums is 100% natural & contains a potent mixture of beneficial bacteria Revitalizes old aquarium water and green or brown water and surfaces Treatment naturally removes dirt and grime from aquarium surfaces & eliminates fishy odors Thoroughly deep cleans dirty fish tank by reducing organic waste & clearing cloudy, discolored water For best results, add Re Fresh water conditioner on a weekly basis to help maintain a clean