XXL Water level indicator

I made this one to always see the nutrient reservoir level in my hydroponic pot. 

You'll need:

• A PVC pipe with an inner diameter of 17-18 mm (Don't worry, you can modify the sizes to your liking!)
• A bit of (styro)foam
• A few plastic straws, or something similar

With the floater, you can remove the bottom layer with a scissor, and then fill it with foam. Then, you clip a few plastic straws into each other, put a tiny drop of acrylic glue into the narrow tube, and insert the straw. 

CAD-file for customization: https://cad.onshape.com/documents/53c18f041783d8f0cabf54c6/w/596d96154938a8f61b9ef06d/e/4d2ebd2a22c98ec5498d6817