Hello ryeookin,
OK, That's a lot to read and try to figure out, so let me start with a few points, then ask some questions. First point is that bulb looks awfully close to the seedlings. Second if the rockwool is touching the water, it's likely waterlogged. Third, seedlings that small don't need much
nutrients at all, and I don't understand how your mixing the nutrients. Can you give volume measurements? How many mL per gallon of water of each (gro-micro-bloom). You don't need a syringe, regular teaspoon's and tablespoons are fine. One teaspoon is 5mL, and one tablespoon is 15mL. Lastly, as I remember the so called "Kratky method" is nothing more than a water culture system without the air
pump.
1. Is the rockwool cubes sitting in water?
2. How are you mixing the nutrients?
3. What is the water temperature (day and night)?
4. What is the air temperature at the plants leaves (day and night)?
5. What is the humidity near the plants leaves?
6. Is the top of the rockwool cubes more wet than just barley damp?
7. Without the
cfl, how much light does the seedlings get?
8. Do you have something against using an air pump?
9. Have the roots begun growing out the bottom of the cubes /baskets yet?
10. What is the pH, and does it fluctuate a lot?
11. What is the chemical and mineral composition of the tap water your using?