I originally bought some solenoid valves to experiment with, but ended up simplifying my approach. I use a submersible pump that is plugged in to power. I can just automate turning on/off power to that outlet (I have two TP-link / Kasa HS300 strips). The nutrients / water are in a tank below the tray of plants, so when the power is "off", gravity brings the water back through the pump into the tank again.

Not OP but I use motorized ball valves from Amazon [1] which are hooked up to a four way water hose manifold to create four different zones. It's wired up to an ESP32 that controls them with relays via GPIO, using the ESPHome sprinkler controller module (which does pretty much everything OP's code does). I've never had a problem with them and the last time I even touched them was over a year ago. They're pricey but you can DIY them.

The usual sprinkler valves at hardware stores need quite a bit of water pressure to change state which is probably what most people have a problem with, especially if they're trying to feed them with the kind of pumps they get at hydroponic stores.

[1] https://www.amazon.com/Motorized-Stainless-Electrical-U-S-So...

Not OP, but I made one of these for my partner and I’s bonsai garden.

I use standard 3/4” sprinkler valves from the big box stores, connected to a manifold via unions on each side. This enables me to swap if needed, but these are ruggedized and will last a while. They do take 12VAC, so you need a transformer and use relays to turn them on, but they work very well.

I know next to nothing about aeroponics - I did read about aquaponics a bit when I started, but hydroponics seemed the most accessible for me.

I've loved making my own crushed red pepper. And there's something fun about growing plants in the middle of a cold snowy winter in the basement.

In practice aeroponics is very fragile. All it takes is a failure for a few hours for roots to irrecoverably dry out and kill the plants. Most hydroponic methods give you a safety margin of days or even weeks.

I agree, a blog post or other description would be great and really inspiring for my own projects.

I use two pumps from Atlas Scientific - one for a jar of base and one for a jar of acid. I have a sensor for PH so I can see in the live dashboard, and can click a button on the dashboard to disperse a set number of ml to the tank. I should have been clearer - PH is the one thing I didn't "close the loop on" because it'd be a little volatile. For instance when you first add nutrients to the water the PH drops steeply but stabilizes over hours or a day, I didn't want to respond too constantly to those changes. I should spend more time on this aspect though and maybe just have notifications for when it makes decisions.

Not OP but I use aquarium peristaltic dosing pumps that pump General Hydroponics pH Up/Down solution controlled by a Raspberri Pi with an Atlas Scientific pH sensor.