I was just thinking about only doing a water change and not dosing anything and if I am right, this will bring the elements to lower level slowly. Example, let's say water is 100L and all elements is about 100 - just for easy calculation. After a week, the elements go to 90 and I do a water change 50% again for easy calculation. Now the old elements at 90 and new elements at 100 will average out to 95. So after a week and doing a water change the elements came down from 100 to 95. Of course in reality, this will be pretty slow but eventually it will add up, so a dosing will eventually require. What do you think? [emoji848] Sent from Singapore Reef Club mobile app