I've looked for hydrophonic tower lid that match this tower: https://www.printables.com/model/720081-modular-hydroponic-tower

Sadly, as I'm not living in the US, I didn't found 5 galon bucket, or a bucket with matched diameter, So I've created one with 34cm diameter.

To help  everyone, I've attched the Fusion 360 file so you can adjust the lid for you side (Just modify the first sketch to your desired size).

Printed with PETG

Use 18 screws and nuts of M3x8 

I've used some M3x12 just because I didn't want to waste so much M3x8