Brussels Sprouts look like mini cabbages since they are members of the same cruciferous vegetable family (i.e. cauliflower, broccoli, etc.).
If you want to increase the size of your Brussels Sprouts, topping them off (chopping off the head of the plant) allows the plant to allocate all its energy towards the side sprouts, thereby increasing the size of the sprouts to potentially reach a golfball size.
Due to their size and weight, Brussels sprouts need to be planted on the two lowest sections of the tower (preferably just on the lowest). Like for other slow-growing large plants located at the bottom of the tower, root management is a must. In fact, over the course of the 2 to 3 months which it takes to grow Brussels sprouts, they will produce a massive amount of roots which will grow straight into the reservoir creating a DWC situation.
We only advise you to grow Brussels sprouts on your aeroponic tower for experience sake only. In fact, Brussel sprouts grown aeroponically give a much lower crop yield than when grown in the soil while monopolizing quite a lot of space on the tower and up taking a lot of nutrients.