It takes at least 3 weeks, my friend.
Of course, the situation varies depending on the fertilizer you use. If the plant is not genetically purple, the reason the pistils are purple is because the weather is cold at night, which slows down flower development. if the plant is not genetically purple, the reason why the pistils are purple is because the weather is cold at night. this slows down the flower development...
!! i think it seems like it is in the 2nd week of flowering. if you are worried because it is in the 4th week, the reasons for this are;
• the weather is cold.
• the color of the light is not encouraging flowering due to the season. or if you are not using additional fertilizer, the soil is deficient in phosphorus.
• or the water you use does not have a pH of 7-7.5, it can also slow it down