Id put them in much larger pots, especially since you say the roots are growing out the bottom, and they haveint been in the 3g pots long. Already took up the space. Plan ahead.
Also I myself never feed, at recommended doses. If it says 1 tblsp per gallon, I give it 1 tbsp per 5 gallons, and feed more often. Then slowly increase feed. Also agree about the magnesium deficiency, and at 2-3-1 the mix is grossly Potassium Deficient. Weed likes the same amount of Nitrogen as it does Phosphorus, and 2x the amount in Potassium. 1-1-2 Ratio. Magnesium is the most common container grown plant deficiency. Weed is very very hungry for Mg. Also loves Sulfur. Sulfur produces Terpenes, especially in late flowering.
. If theyre in 3g, Id put them in 10 gallon.
Leaf curl is a tell tale sign of over fertilization, or lockout.
How much I water depends on the Light Used, Temps, and if you have fans blowing. I like fans 24/7. Even when lights out, though I veg 24/7.
In a 5 gallon pot, Id give no more than 1 gallon of water depending on the texture, and water holding capacity of the soil. I mainly use Promix BX.
What Id do is get a cheap Lowes/Walmart Ligh-Moisture-PH Meter, and use it to determine exactly how wet/dry the container is. Ive used one for over 40 years. I dont need it now, but I still use it, as it takes all guess work out of it. I measure in several spots in the container, and well as towards the bottom/ via lower sides.
I never let the Needle get to the Dry Line, always to just above a fraction, and if it takes more than 3 days for a good size plant to dry out to the Low Moist area, its had to much water, and I will give slightly less next time, or more if it dries out to fast. I measure it everyday. Many times 2x just because.
In a 20 gallon container of Promix BX, under a 1000w Hortilus HPS, and a Super Silver haze we have, at its biggest intake, it uses 3.5 gallons of water every 3.5 days, at 82f-86f temps, and a stiff breeze 24/7. With heavier soil, expect slower use/evaporation times. Probably water less. But keep the no more than 3.5 days watering schedule.
Its also a MYTH to cut back Nitrogen in flowering.
Say one has an 8 weeks flowering strain.
The plant needs more of Everything during flowering, as this is when it will have its largest Biomass Growth Spurt.
All Nitrogen is, is Protein. Humans eat Chicken, Fish, Beef ect, and our bodies turn it into Nitrogen. Plants just skip the breaking down phase. Would a Bodybuilder limit Protein if trying to Grow?? No, its not logical.
At 2.5 weeks- week 4 the plant generally like a 0-52-34 Mono Potassium Phosphate Boost, along with slowly increasing amounts of Base fertilizer. And Magnesium. I like Epsom Salts, as it also supplies Sulfur...
In week 5-6 MPK is stopped, and in weeks 5-6 the Magnesium is increased, with small increases of base fert.
In weeks 7-8 fert is decreased 40%-60% but not totally stopped. Flushing is a myth.
Also make sure you have the best air flow, and ventilation possible. Remember the less light, the less water, and food the plants will use. Weed gets strong light in nature. Think how powerful the sun is in Equador, in the Andes Mountains, at 8000 feet???? More light also equals more air flow needed.
