You can mix a capful of D-Klor with 2 cups of water and then add this into your tank (I pour it through the feed cap for convenience).
D-Klor is all natural so don't worry about adding too much, it can't harm your fish.
- Your fish does not need to be taken out to top it off.
- What I normally do is just add Dklor into the cup I'm topping it off the tank with and then just pour the whole contents into the tank.
- One suggestion that I've heard is to get a gallon of water and put the Dklor into the whole bottle. Then you'd keep the whole thing near your tank that way you could easily just pour water into the tank without going through the extra step of adding Dklor each time.