It means the spacing between your nodes is not optimal. So you will have to work those plants to get all of the branches (node tops), to be even in height, so when you kick the plants over to flower, all of the branches (node tops), will get the same amount of light throughout the flowering cycle! Anyhow, if they were my plants, the light would be coming way down, because elongated (nodes) usually means the plant is reaching for the light! So either lower your light, or crank up the power, but lowering is always better. For me... I always choose to lower the voltage, and drop my lights during veg. I keep my my lights at 12 inches at all times, and I run 288 boards at just 40 watts each, two plants under each board when they are less than (4) weeks old!