I have been running the current setup since about mid February with ok results. I'll explain the setup later or in the instructions. First fill was with about 5 liters of water and a cap full of nutrient. Within about three days I had a massive algae bloom, white and slimy. The algae had clogged up all the spray nozzles. As I had only just put seeds in the substrate at this point it wasn't a big deal. So I flushed out the system and replaced the clogged nozzles. Figuring that I had over fertilised I only put a tiny splash of nutrient in the new mix. This seam to work and haven't had any algae issues since. As the plants have grown each top up of water has slightly more nutrient.
A fairly constant issue is that the nozzles with clog from time to time. While it's quick and easy to clean, I intend this project to be little/no maintenance, and if I'm away for a few days this clogging issue could lead to disastrous consequences. I've been toying with the Idea of print my own nozzles that are less likely to clog.
I've also had to put up a heat shield. The afternoon sun can get quite hot, and at one point some of the little plants did get cooked. The basil can be quite sensitive to too much direct sunlight. The slow starters were the cucumber seeds, however so far these have proved the most hardy and the fastest growers. The lavender has sprouted, but remains shy.
The watering system is on a 15min on, 15min off cycle. I might change this up a bit as winter approaches. I've topped up the water about 2 or 3 times (between 2 -5 Liters each time) since the algae purge, which isn't too bad for how hot it's been.
This setup has worked better than I thought it would. I would like to reinforce the supporting structure underneath the growing substrate - bent wire coat hangers really don't cut it. Maybe throw some more seed varieties in and see what happens. I'm more or less going to lets this system go and see what it does with out too much interference. This was more of a proof of concept to see if I could grow anything before investing more time and money into the project.
The next step will be to design a larger system that will span the length of my balcony and support more plants.