Answered by Shaykh Faraz Rabbani
1) I normally remove my nose-ring (a very small speck of a stud) during my shower ghusl. I recently forgot to remove it, performed ghusl (sniffing water up my nose during the wudu portion of my ghusl), and prayed dhuhr. Is that ghusl valid? Would all subsequent prayers need to be repeated?
2) For at least 6 years I have followed my “amin” after surah fatihah with “sadaq allahul adheem”. Are all those prayers invalidated and therefore need to be made up? Is there any school of thought that would consider my salah valid?
3) What about saying “aoodho billahi min ashaytaan arrajeem” before every fatihah in your salah? Is that ok or does that invalidate the prayer?
Walaikum assalam wa rahmatullahi wa barakatuh,
I pray this finds you in the best of health and spirits.
 You can assume that the water reached under it, and that your ghusl and prayers are valid.
 Saying that wouldn’t affect the validity of the prayer, as it is merely dhikr, though it is not the sunna (nor proper) in prayer.
 Saying that before each recital of the Fatiha doesn’t affect the validity of the prayer, though the sunna is to only say it before the first Fatiha in prayer.
[ Shurunbulali, Maraqi al-Falah with Tahtawi ]
And Allah alone gives success.