Replanting the Aerogarden

I've had an Aerogarden Hydroponic Garden for years.  It was steeply discounted.  When I used the original seeds, tubes, soil, and tablet feeds that came with it, it flourished, though one plant overtook the others creating a root mess.  Like many things, they sell you the unit at a discount but gouge for parts.  I have little choice but to replace the proprietary fluorescent bulbs at a premium price periodically but have tried to go cheap with the other elements.  Potting soil I always have.  Herb seeds I always have more than I can plant outdoors.  Nitrogen supplements have not gone well.  And one plant still takes over, this time tarragon, usually basil which grows like a weed in a hydroponic setting.  

After leaving Aerogarden untouched on my Daily Task List for months other than topping off the water, I set a fixed time to give it another go.  It has six tubes.  French tarragon dominates, needed a big harvesting trim.  Some chives with benign neglect are holding their own.  Not enough for flavoring, maybe for a light garnish.  And one tube has slowly growing thyme or oregano, I can't tell which.  That left me three tubes to replant.  Coriander never takes well.  Dill sprouts then withers.  Basil takes over and I have two flourishing plants in terracotta chia pots adjacent to the aerogarden.  Start with sage.  I had plenty of sage seeds.  When I took the tube out, the soil only covered the upper half, so if it ever got roots they would have a gap between the soil and the water, though since the soil felt moist, there must still be some diffusion.  I pushed the soil to the bottom of the tube, added some seeds, tamped it down, and replaced the tube in its set location.  Then some water, then a cover, once a transparent mini-applesauce cup, with a marker to tell me that cylinder has sage.  Next some parsley planted with the same procedure, then some oregano.  Topped the reservoir with water and check for germination in a few days.  Sometimes you make it and sometimes you don't.  Plus, I now have a lot of harvested French tarragon in search of recipes.