Bioactive Tapsafe removes these nasties from your tap water. It also adds soothing aloe vera to help protect and heal fish skin and gills, and beneficial bacteria to help maintain a healthy balance in your aquarium. The result? Perky, happy fish full of vigour. Use to treat fresh tap water before you add it to your aquarium. For instance when setting up a new aquarium, doing a water change, topping up your aquarium or when adding new fish.