Thank you all for your comments, i'm very happy.. the HC cuba is growing already with only 4 days after planting. Well I have to admit, I have used ADA Green Gain, because as you know the HC takes a little time to accustom in the tank, so I change the water daily and i add 1 drop of green gain and a little portion of micronutrients, the plant says "thank you" and we can see her already spreading the leaves.
All plants love fresh water.. that's the key...
Here is the picture:
Best Regards
Ricardo Rosa