Hello so there have been a lot of thunderstorms recently which is why I have been kind of scared to do ghusl in the shower. Because of that, I took a cup of water to rinse my nose & mouth. Then I filled a bathtub with water and washed my whole body with it once by immersing myself in it and pouring that same water over myself with a little bucket several times so that it reaches all parts of my body. I didn’t do wudu afterwards, I just got up and prayed. Was my ghusl valid? I really don’t want to take showers during thunderstorms so I didn’t know what else to do.
From my own knowledge I understand that for a ghusl to be valid it must meet the 3 obligatory criteria which is to make the water reach the nose mouth and then wash all the body including the head making sure all parts of the body is washed. This must be done with clean water. But I believe from the way you described it your ghusl will be invalid because you reused the water which would have been in contact with the impurity. To avoid this you could just use a bucket of water and use a small cup to pour water over your body as you will be using clean water rather than the same water already used.