I wanna share with you the so called “Kratky method”, a hydroponic way of growing herbs, leafy greens and all sorts of stuff without any growing media.
I use glass bottles, which I made a nice 3D-printed adapter for. It fits an optional wick (useful for the start) and holds everything in place. You can even refill them later on!

Plant roots need both oxygen and water. If you only put them into a full glass of water, they’ll die due to suffocation (“overwatering”/ root rot).
In the Kratky method, the level of the nutrient solution drops as the plant grows, and oxygen is provided that way.


I really like this method for growing lettuce on my balcony.
The main benefit, compared to a classic growing medium like coco coir (or even soil), is that you don’t even need any growing media you have to dispose of later on. Zero waste.
And of course all those neat other hydro benefits, like fast growth, less pests, and so on.







I’ve used my 3d printer more for hydroponics than anything else. It’s great for making baskets/adapters to hold sprouts in whatever container you want. I settled on 2" PVC with ebb-and-flow irrigation, but Kratky fascinates me.
Do you have trouble with algae in the glass containers?
I love the Kratky method especially for easily disposable fast growing short lived stuff like lettuce (1-2 month grow cycle).
Other methods like your ebb and flow is better for high value crops like chilis and weed imo :)
With clear glass, which I used in the beginning, definitely yes.
With green/ amber ones nope, or at least only veeery weakly.
Currently I try spray coating a few ones with white pigment, and see how it turns out with heating up in the sun and algae compared to the uncoated brown ones.
I’ve done a fair bit of kratky and dwc. Typically you avoid algae and other root rot issues with opaque containers.