Read the back of the tub,this is by far the best way of getting the best from any nute package, all though i would not use mj.But i have seen some great results from this feed, but if you can get hold of another brand then do so, you realy want a feed that is made for the cannabis plant.And in my own experiance of feed's and i have tried many well all of the big name one's and none come any where near advanced sensi pro a and b veg then bloom.If you are gonna use mj then there is no ppm reading on the back like on advanced so you will need a ph and ppm metre to get the best from the feed.Round about week 5 get them on 1800ppm's what ever the feed and a ph of 6.2/6.5 in soil 5.2/5.5 hydroponic's.But if you do decide to change yr mind on the feed then do advanced then you will have to take one reading,this will be the reading of the tap water,without the nutes added and take this into consideration when makeing a vatch up.But i still check the ph and ppm's every so often even though the nutes from advanced are all ph and ppm perfect,this can be a god send when you first start out.Every reading that i have ever taken when adding a certain dose has come near perfect to what it said it would on the bk of the tub,and i have made batches up in several differant locations with all differant water ph so it defo work's the ph perfecct thing.do your self a favour ditch mj and go with advanced.......................................tyke.................................................................