The fabric pot would have to be in a pot that could hold at least some water in a basin - don't want a puddle so, what doesn't wick up into pot you'd have to remove.
You also have to deal with evaporation over time. Something ~20% runoff takes care of.
I have a setup that basically bottom feeds like a hempy, but with a res for about 1/2 gallon that's oxygenated with an airstone. No light gets to it etc... small enough that the plant drinks it down quickly to avoid buildup a bit. Before bloom i have to add a dose of pH-only occasionally (coco). This accounts for concentration due to evaporation. By bloom, it drinks it down so fast it doesn't matter.