What is the difference between Flex Tube and Silicone Tube?

Hi, as the title says, can someone inform me what is the difference between the 2 tubes (Flex Vs Silicon)?

Which is for what use?

I will buy a 2.2 Maxi SA that I am going to use for ATW when home but to feed liquid food while on vacation (new set up while on holidays).

Which tube should I buy?

It comes down to what you'll be dosing or pushing through the tubes. For example, the KHD water sample, waste water and vent use silicone tubes for normal saltwater. However, for the KHD reagent, flex-PVC tubing is used for minimizing oxygen exchange from the outside of the tube which tend to cause air bubbles for this kind of solution.

Silicone has more flexibility to it whereas Flex-PVC tubing is more "stiff". If you're going around tight corners, the silicone tube may be better for your 2.2 Maxi.

Perfect explanation, thank you so much!