Plant watering is probably the most solved problem of all for this project. There are probably thousand different ways to water your plants (semi) automatically.
So I wanted to integrate with a solution that is readily available and cheap.
Luckily the most readily available solution are these dripper watering sets that come with 6mm tubing which fit perfectly well into a 5mm fuse clip.
You can get a set for 12 plants at about 6€ at Aliexpress: https://www.aliexpress.com/item/1-Sets-Fog-Nozzles-irrigation-system-Portable-Misting-Automatic-Watering-10m-Garden-hose-Spray-head-with/32685122008.html

You can also get the cheaper orange ones where you get about 50 drippers for the same price. The grey ones are actually spraying rather than dripping.

Though that is just one part of the problem. You also need a pump, first I thought it would be more economical to use a single large pump for several plants and control water intake with a solenoid valve. Though I quickly discovered a small water pump that is readily available on ebay and aliexpress that is just 1€ more than a solenoid valve, so its a no brainer to let every plant or "system" have its dedicated pump.
You can buy one of those pumps here for ~3.40€
https://www.aliexpress.com/item/High-Quailty-Ultra-quiet-DC-12V-4-2W-240L-H-Flow-Rate-Waterproof-Brushless-Pump-Mini/32830067673.html

They are small enough so you can actually mount them on the metal rods as well which I will do next! For now I just put in on the floor to test my tube clipping mechanism. Here is a full video showing everything:

You don't have to put it on an extra arm of course. Here it spraying from the top, from the same the led module sits on. The fuse clips are perfectly comfortable holding larger loads, you could probably add two more light modules without any issues.

Next up is a dedicted PCB to hold the water pump vertially at the bottom of the rods to make the whole thing more self contained. No one wants a bunch of little pumps scattered around their floors...