Hydroponic plant holder mk2

This is a followup to my previous plant holder. Most notably this one will fit the standard 40mm rockwool cubes I have, no need to cut to fit anymore.

The old design ended up failing near the top where it was exposed to sunlight, this design has thicker plastic to provide some extra support.

I've also reduced the number of holes / made the holes larger. It will still print fine without any support material but it will be easier to remove old plants without damaging the holder.