I use FF ocean forest soil, hope it's classified as organic
I purchased an RO system this grow so instead of using a 20% tap water and 80% RO, I used 100% RO. This led to a cal mag deficiency. The calcium deficiency seemed to appear 1st. I used GO cal/mag alittle to sparingly at 1st (I always try to stay on the side of under fertilizing) then I needed to kick it up to 2 tsp per gal when watering and as a foliar spray as my upper fan leaves, were developing necrotic spots (IMHO a calcium deficiency). I had 3 strains that were reacting differently. Some showed no deficiency, some had necrotic spots on the upper leaves, and some had the classic look of a lower fan leaf mag deficiency. Some developed purple stems. (Probably from the mag def). More plants over time developed all 3 visual types of deficiencies.
Not all plants got the same feedings.
General Organics Cal/Mag was used as described above.
Each plant got a tbl of ff happy frog bat guano on 2 occasions 1st week of flowering and the 4th or 5th week of flowering.
Each got about 4 feedings of FF Big Bloom (about 2 tbl/gal) starting near the end of veg and ending between the 6th or 7th week of flowering.
Some plants received Epsom salt, gypsum, and lime in small quantities.
Some plants got none of the above some got one two or all 3 off the above.
I started with FF light warrior after germination before moving to FF Ocean Forest.
During the seedling and early veg stage I used a 600W MH.