Yea chrissy that could be an issue, but it's very possible to harvest an oz ,stealth grow to the max.Like kind princess said, that incandescant light is doing nothing to the plants at all. kb the 20 watts youre talkin about are compact cfls. The spiral shaped bulbs u see at lowes/home depot ? 23 watt compacts is what u want ,go get a little table lamp and a bulb right when you read this bro,lamp for 15 bulb for less than 5. Good luck keep us updated.