You can hang the controller inside the greenhouse as long as the glass is clear and the solar panel is not in the shade.
One Irrigation Unit (IU) is typically the amount of water need for a tomato plant - 1 dripper should be used for each tomato plant.
If you are also watering pepper plants they need roughly half the amount of water, so 1 dripper can be shared by 2 pepper plants. Alternatively you can split a dripper by pushing the tube onto the end of the dripper and adding a t-piece connecting to 2 drippers.
You may need to purchase extra drippers, t-pieces and stakes which you can buy in the
spares section of our shop.