I put the plants into an NFT system couple weeks ago. I could have waited a bit longer for the plants to develop a stronger root system before placing the rockwool cubes into NFT but I was being impatient because of the slow start and wanted to get the plants under proper light. Now two weeks later they are growing well with good root development. I switched the lights to flowering cycle about a week ago so they should start stretching soon. No preflowers yet.