Heya,
Top pics look good... notice the seedling pics are showing lots of stretch...
A good way to avoid that in a hydro setup is to start your seeds in rockwool plugs and hand-water them for the 1st couple weeks. Then when they have developed some more you can bury them up to the cotyledons in your hydroton. You end up with some stem buried that can develop roots, and more control over any stretch that occurs.