had an aerogarden once, sponges is about what they used, so i did an experiment, i cut up a sponge into strips, cut a notch in the middle of each one, and put seeds in the notch, put them in a cleaned out wipies container, had a very low level of water...they all sprouted up fine...of course this was years ago, before i found rui, and never had any indoor experience, and with no one to tell me better, my stupid ass used an agro light, which worked for the first couple of weeks, and then they just started dying...either from the heat or lack of light, not sure which...