Yes you can!
I currently have 3 different strains doing well and in the final month of flower- all without fertilizer (mostly- I'll explain).
For each grow I am using a Roots Organic Original amended with dolomite, epsom salts and diatomaceous earth.
Sativa (heavy feeder)was grown with multiple transplants - solo cup for 2 weeks- then a 1 gallon container for 3 weeks and then a 3 gallon container just before the flip.
Sativas are heavy feeders and began yellowing at the start of 12/12- lower leaves (but this has a long flower period of 10 weeks)-so,I added 1/4 flowertabs (organic- Nirvana Shop) and gave a very small dose of dyna-gro bloom to help before the flowertabs could kick in.
I then added another 1/4 about 14 days later. Next grow- I will use 1/2 flowertab with 30 days between because the flowertab would be used after about 6 weeks (I assume as Nirvana hasn't returned my email concerning the duration of action for the flowertab).
The Sativa was heavily LST/HST as it grew too large while I was on vacation.
Indica (average feeder)- the seed was planted directly in a 2 gallon container- (using a germination bag) and was doing fine, but I decided to add the low dose of flowertab 1/4+1/4. LST only to break apical dominance. water only
Auto (light feeder)- same as the Indica- except it is a light feeder and the flowertab (organic) full dose is 1/2 tablet and was added once pre-flowers showed. LST only to break apical dominance. water only
I do use Protekt, and General Hydroponics pH UP on all grows
I added 1 feeding of epsom salts to the Sativa.
I keep Dyna-gro foliage -pro and bloom on hand should a deficiency show up- but only used 1/2 ml of bloom on the Sativa.
With this set up there is no need to flush the plants for harvest and I have not run into any pH problems-
I like Dyna-Gro as I "could" use it and it does not need to be flushed - regardless of the low dose that I had to use- once.
