Great question! 🌱 You’re absolutely right that in soil-based gardening, companion planting plays a huge role because of how roots, microbes, and soil chemistry interact. For example, basil and tomatoes influencing each other’s flavor is a soil-and-terpene relationship that gardeners have observed for centuries. In hydroponic or aeroponic systems like towers or NFT, things work a bit differently. Since there’s no soil, plants aren’t exchanging nutrients through microbial activity in the same way. Instead, all plants share the same nutrient solution, which you balance and provide. That means: - 🌿 Flavor enhancement (like basil + tomatoes) doesn’t really transfer in hydroponics the same way—it’s not about shared soil chemistry, but you can still grow them together successfully without issues. - 💧 Nutrient depletion or replenishment is not plant-to-plant in hydro, since the reservoir is the source. If one plant is a heavier feeder (say, tomatoes), it will pull more nutrients, but it won’t “add back” nutrients for the others. That’s why monitoring and topping off your nutrient solution is so important. - 🚫 Allelopathy (plants releasing compounds that inhibit or harm others) is generally a soil phenomenon. In a shared hydroponic system, those interactions don’t really happen in the same way, so you won’t have one plant “killing” another through root exudates in the reservoir. The main thing to keep in mind in a tower or NFT setup is growth habit and light competition—for example, a tall, vining plant like tomato might shade out leafy greens, or large root masses can crowd smaller plants if the system isn’t balanced. So while companion planting as it’s known in soil doesn’t fully apply, strategic pairing in hydro is still important—but more for space, lighting, and nutrient demand balance than chemical interactions.

Your first set looks much better for sure. However, your bean vine was also getting more greedy with the nutrients that everybody was sharing. I don't think that this is the problem nearly as much as the Chloramine in the water. Also check that your ph. for seedlings is set around 5.8 - 6.0. I retract my previous statement about your tap water. Even a ppm of 1 chloramine can stunt your growth. I'm glad that you brought this to my attention (I got to learn a thing or two as well) it just comes back to RO is always the way to go.

@Gillian El Deeb I would get a drinking water RO system. That will guarantee the best results.

@Gillian El Deeb What I see here are a couple things. There seems to be a higher than usual concentration of moisture at the top of your net pot. This is causing rapid nutrient salt buildup and the roots to grow out into the air. There may even be some Mycelium forming there, I just can't tell if they are root hairs or mycelium. This is likely because of your rockwool being too wet and the roots then not knowing which way is up or down. The moisture then rises out from the top of the cube and leaves behind the salts. It happens more with slower growing plants, so I am not surprised to see this in your garden. Here is what I recommend: Get some 2 inch foam cloning plant collars. https://amzn.to/46SEtSo they spread apart so that the plant goes in the middle. Remove the clay pebbles and insert this collar around the plant, setting it gently in just the top of the net pot. This will prevent moisture from rising out. My guess though is that all of this will be fixed by a water and nutrient change. Even tap with your 45ppm EC would be totally fine. however your plants wont immediately grow back, they may have nutrient salt buildup. That may mean you would be better off starting from square one. Although you could clone your basil, all your herbs, chives, celery and greens right into your garden. giving you a full bushy garden, larger than what you have now, in about a week through cloning.

I went to art school for photography and I was playing with "painting with light" when I took this picture. It totally popped into my head when I read your joke. 🤣🤣

@Gillian El Deeb There is one key factor at play here that is causing your growth issue. We are running through all the possible variables to single out the root cause/causes. Once we do, thigs will be smooth sailing and you will have learned a lot!

@Beth E This is a bacteria or fungus on your cut leaves. This can happen where there is less airflow and more humidity. That would be something air born, not from your garden itself.