MrStinkyanswered grow question 3 years ago From the first pic it could be calmag - are you under LED too?
Are you using easy bloom every time? (I use the RQS nutes, they are great). You can use every watering indoors, especially in a light mix soil, but aye, stick with half a tab per 4L say
If you are adding calmag, dont go wild as this can cause issues of its own.