Big Rootz/Mr B’s green trees

How long will Big Rootz sustain a plant before I need to add nutrients?
They will be vegging in a 1 gal to a 5 gal for the entire veg. Going to veg for a month and a half and then transplant to a 10-15 gal pot, wait two weeks then flip over to flower.
Was going to try Mr B’s Green Trees 2-8-6 as a top dressing for flower but I don’t want to burn the plants and wondering if big rootz will be too hot to add anything at that stage.
let me know if you have any experience with these two products.
Thank you everyone!!!

Depends on container size/how much soil you give the roots. If you give them a full 2 cubic ft you should be able to get them through a few weeks of veg and a good 8 weeks of flower. If you put them in little pot like 10 gallon they will not make it all the way through without adding more fertilizer of some form. If you want to stay organic you could always just feed a product like Green Planet Medi-One or something similar during bloom...

Organic doesn't always mean safer though if you read the bottle it has a warning about heavy metals right on it. Fish poo can have high levels of toxic metals in it same with dirt. If you wanna know why to be concerned of heavy metals google it, early onset alzheimer's, bone cancer and more goodies are directly linked with its consumption.