Royal Dwarf

We had a quite satisfying 1st week i must say. The seed sprouted well, the transplant to final pot was smooth, and thanks mother nature it germinated out of the soil and we have a little baby on. I have covered the little plant with a plastic dome to protect it from predators and keep the humidity high as advised. I am not sure if my "dome" is ok please let me know if you notice anything that i must change immediately. I am feeding the little baby with water only with a pH of 6.8. I am very afraid to use tap water as i am not sure of the level of acidity. I am expecting to get hold of a pH paper to test the tap water first then i will decide. For now i am buying bottle of mineral water. I can also be wrong here so please let me know if i am. As advise by some growmie, I am giving the baby 150ml of water nearly every morning, I let the soil dry a bit for the plant root to get the oxygen needed for the growth. Day 12: I took some photos to get some comment from you guys. I need to know if the long stem (whitish) look ok and if the yellowish leaves look ok as they seem to fall instead of being firm? Thank you for reading