The following video will show where the glycol tank is located in the following units

Pre 2021 TAB 320

TAB 400

Cirrus 820

 https://www.youtube.com/watch?v=WauzRYpGhhg&list=PLCMrvBGaOplpkvlu_zIsW-YZdR_qelvxo&index=1 

Cirrus 620

For 2021 and newer TAB 320 S and CS-S please see the following

The glycol tank on the 2021-22 tab 320 S and CS-S is in the bathroom – underneath the sink and above the toilet. The panel is held in with screws and the screws have caps on them that need to be popped off to expose the screws. Remove this panel and you will have access to it.