I started lotus seeds also, started indoors, and at first site of secod stem I mushed them into soil outside pot with 3 inches of water so the seed casings wouldn't start to go bad in open water now that they are planted. About 4 leads appeared on all 4 of 6 and the last two did nothing.
Then we had a cold rainy spell, they stopped growing for week or so, and now have taken off. One even has a runner formed. Will take picture and post when I get computer. The one with runner was one of the two that didn't put up all four leaves and I thought was dying back.