Just keep in mind, soil offers are wide range of nutrients already, while there are no ready to use nutrients in hydro cultures. So the cannabis hydro culture needs more nutrients and another relation of them.
Some fertilizers come in 6 up to 12 different packs, so that you can always ensure the best nutrients and the best relation of them for your cannabis plants. Since fertilizing can be so complicated, the packs with the various fertilizers are normally delivered with a schematic when to use which of them.
For example right after the germination of your cannabis seeds you give enhancers for the root growth, the fertilizer has instructions in the manual how much you have to use per liter of water.
Some fertilizers add another one during the second week, to not only enhance the growth of the cannabis plant roots, but also already enhancing the plant growth.
And so it goes on during the cannabis vegetation period and the cannabis flowering period, most fertilizers fully stop 1 or 2 weeks before the harvest. Of course the root growth hormone is regular only given when the cannabis plant is small, but especially during the early and mid flowering stages it can be possible that you add up to 4 different fertilizers at once.
When you want to make a decision for a fertilizer, be sure the time frame on the fertilizer fits to the times given to your cannabis strain. Cause many fertilizers have a 8 weeks cycle in their manuals and it will become difficult for you to adjust it properly when you got a cannabis strain with 12 or more weeks.
If you can´t follow the instructions of the fertilizer properly, it can easily happen that you give your cannabis plants too many fertilizers. That can be the death of your grow, as fertilizers are highly concentrated nutrients and could even burn the cannabis plant roots.
But be aware, natural fertilizing also raises the risk of vermin and other bad stuff to reach your cannabis plants. So in the point of safety, the chemical way is by far better. If you have to keep your purse in mind, than of course the natural way is much cheaper, cause in most cases you don´t have to pay anything at all. Artificial fertilizers can easily cost a small fortune, if you buy a complete set of fertilizers for all stages, than you can quickly spend several hundred Euros. Sure it also depends on the amount of fertilizer within each pack or bottle.
Using the correct fertilizer at the right time is necessary for optimal results on your cannabis growing!