The difference between the Bagtanks is storage volume. So Bagtank choice depends on factors like total daily consumption and maximum peak consumption. The production output of the water purification system connected to the Bagtank should also be considered, as that will impact which Bagtank will cover your lab water consumption.
The biggest benefit is the cleaning process when compared to a standard storage tank. Cleaning a standard tank requires chemicals and a lot of time. The chemicals add the risk of contaminating the water and introducing chemicals into the system. With the Arium® Bagtank, you can forget all about that. Bagtank-bags are disposable, so instead of cleaning you only need to change the bag. The process takes roughly 5 minutes as opposed to several hours.
Yes, you can connect 1 Smart Station Pure to dispense RO/pure water (depending on water purification system) directly from the Bagtank.