If you have a reverse osmosis system in your home you need to change filters. Read up on the brand you have and be sure to follow the instructions and change it, this will keep the water flowing. Also you will need to change the membrane since on so many units you only do every four- or five-years people seem to forget it. The membrane is what makes the water into bottle quality water, it will remove 97.6% of everything. The other filters remove the chlorine, herbicides, pesticides, and organics but for it to be bottle quality the membrane must be functioning.
So many people never add air to the tank, this is important to know because the water in the tank is inside a bladder that is inside the tank. When you put air in the tank it pushes against the bladder to make the water come out. If the air gets low, you will not be able to empty the bladder to full capacity. You will get like a half of coffee pot and it will stop. There is a place on the back of tank just like on a bicycle tire then you use a bicycle pump to put the air. You need to be careful if you over fill with air you will bust the bladder. Yes, the tank can be ruined so, empty the tank of all water. Add air usually around 6 or 8 lbs of air which is usually a half of pump. If you want to know more there are quite a few videos on You Tube.