I have water about 1-2 feet underground from a nearby stream, how high above the water do plants need to be? Will they drown if the roots are in water? It is also spring so I assume the water level will only go down from here? Thanks.
If the water is oxygenated enough they will survive. But managing nutrients would be close to impossible. If you want to grow plants cheaply then try soil, or if you want to do hydro then deep water cultures and hempy buckets are cheap and simple.