Hi. Thanks for the tips.I decide to reposition my barrels nearer to kitchen. Placing them in the toilet wasn't a good place . I can easily mix salt and let it dissolve overnight and get to at least hide the barrel. I am using a siphon straight to drain when doing water change. Additional barrel is not feasible as lack of space. I normally would measue the surface vol that I require , mark out on the tank side and let the water drain until the level.