[fishscale]

Make sure you can grow HC submerged. If so, you should be ok when you add water. Emersed growth is best used to establish roots and to grow plants cheaply (using sun and atmospheric CO2 instead of injecting), not as a substitute for growing it the old fashioned way.

 

[fishscale]

You could, but it would be a waste to use excel instead of using the benefits of emersed growth. Excel provides carbon, which can also be provided via CO2 injection. However, since you are growing it emersed, the plant can just get the CO2 from the air. You don't need that much water, just enough to keep the substrate soaked. Cover the tank with plastic wrap to keep it moist, give the HC micros and macros however you want, and give it time. I have to warn you, it can be very frustrating watching HC float to the top in big chunks after growing it emersed. Start with fine substrate that is heavy.

 

[fishscale]

It seemed to have a negligible effect in my case. I'm just annoyed that the bulk of my emersed HC floated 10 minutes after I filled the tank on pins and needles. Stupid SMS.