I do not use these for hydroculture, but for starting the plants for my home garden. I have had great success using the horticubes to germinate all kinds of vegetable, herb, and flower seeds. Some of the things I tried this year are: tomatoes, peppers, chard, broccoli, cabbage, tatsoi, cauliflower, malabar spinach, strawberry spinach, foxglove, columbine, aster, basil, parsley, celery, johnny jump-ups, chamomile, chives, lettuce. The brasaicas germinated within 72 hrs. Even the foxglove and columbine is germinating nicely. And no sign of disease or damping off yet. I used the medium thin size for my home garden needs. i don't think you would want to keep most things in the horticube for long enough for the roots to permeate the bigger size anyway... After they get their first true leaves, they will need dirt. A reasonable and reliable way to start your seeds!