Hi Stefan, firstly, I built the 3.0 version. I used Pepsi bottles for the top 4 bottles, and a typical F&N one for the reservoir bottle. As for the netcup, I actually used a 8.5mm (#85) plastic garden pot instead. (There are holes at the bottom, don’t worry.) Found that these fit in the pepsi bottle nicely. I experimented with many different shapes and sizes of bottles but only found this combination to work because of the pepsi bottle’s slim design, I suppose. The pot sits just nice in it. If the diameter of the pot is too small for you, I have seen a slightly bigger example showcased at Changi City Point, Soup Spoon restaurant. I’m guessing they used Ice Mountain mineral water bottle, and a typical hydroponics netcup. They have rows and rows of it there. Sadly, I don’t think they’ve maintained it very well.

What do you mean when you say you have not found a good connection to the reservoir, to the tube?