Tank takes long time to fill, troubleshooting:
Please make sure that the RO system you are using in conjunction with the tank is working properly. Most filters need to be replaced every 6 months to a year. Please make sure your filters are not clogged. Replacing the tank again, will most likely give you the same results if your filters are clogged. If you recently replaced them, please make sure the needle valve to the water is not clogged either. That can cause the system to back up due to normal ware and tear of the unit.