As you can see, the first two plants look quite good while the last two leave something to be desired. The leaves on the back left are curling downward and

https://professional.floragard.de/en-gb/handel/suchergebnis/indoor-soils/650/floragard-professional-growmix says it has about 4 weeks of food and that is going to be variable by plant. If you also cut it with biobizz 'light mix', that'll further reduce the 4 weeks of food. the biobiz light mix has a charge similar to promix, that i am familiar with, and that barely lasts 7-10 days, and they instruct you to start a feeding regimen within that time. I'd treat this like a soilless context, because that's mostly what it is and by this point the medium is running out of nutrients unless you further amended it. Also, looks like bad watering habits, possibly. Heck as long as you stuck religiously to the 10% runoff from the start, you could probably fertigate from day 1 without an issue. the 'florogard' stuff may make waiting a week or 2 wise, though. Observe and adjust behaviour.. see paling? you know to start sooner next time. Be systematic. take notes. Fertilization is about months of time, not last night's irrigation. So, a full and complete diet should be provided every irrigation somewhere around a total EC of 1.2-1.5. Observe and adjust from there. Local variables makes for different solutions for each garden - cause and effect, not magic. 1) Fertigate each time with 10% or more runoff. The runoff is essential. 2) wait for top layer to dry and repeat. How long you wait between is a choice to some extent, though if you water too soon you will cause rootzone problems. If you water too late, you cause wilt. Avoid both. Ramifications of not doing this could result in what you see, but so can a few other causes, too... There are free apps and websites that calculate ppms from gauranteed analysis labels and dose given. I'd shoot for something in the ballpark of... Elemental PPM: N 120-130 P 40-60 K 180-200 Ca 100+ Mg 75ish S 100ish This is a fairly low concentration that would be safe to start. Again, observing and adjusting to your local variables is absolutely necessary. It is not 'my' formula. It's what results from numerous soilless/hydro products out there -southern ag, jacks, masterblend, mega crop, crop salts et al... it's based on the same foundational knolwedge and research. this is a 10x better place to start than any esoteric marijuana brand formula. Do well with simple methods first before doing crazy shit, lol... form a good baseline of expectations so you can recognize magic vs real effects. some apps can calculat dosage from targeted elemental ppm. You can make more than one brand work. Brand is mostly meaningless when it comes to fertilizers. One other note -- converting ppm from EC is inaccurate and not equivalent to the above ppm values that are calculated, more precise and more accurate than an EC conversion will ever be.

Hei growmie. I'm not the most experienced user here, but i can review myself in some of tou description. From what you have showned it seems that you are on week 3 or 4, and for the signs that the plants are showing i would review if you are not under/overwatering, and if not i would evaluate if my light is too week (not probable, when considering the plant growth and struture), but what it seems to be is that since you are using a light mix, you must start your liquid ferts or ammendements. Since you are growing organics, from my experience you can easily show this defeciencies if under/overwatering. If now its probably the beginning of a nitrogen deficiency. Depending on your nutrition plan you should feed a bit more nitrogen (grow fertilizer) than usual to correct the deficiency. I hope i helped in some way, send me dm if want to detail more. Best

Light mix comes in around 1.2 ec so it's only going to support a couple weeks to veg, about now is when I'd start feeding a full and balanced diet. Leaves laden with water, heavy tips wrinkling. Water is not leaving as fast as it wants to. Guessing your temps are around mid 70s F with moderately high rh of 55-60+. Just a guess. A good nitrogen fertilizer with sulfur is ammonium sulfate, magnesium sulfate, plant need calcium at 3-4x rate it needs magnesium. You need to make sure you are applying a full and balanced fertilizer. N,P,K Ca , mg and sulfur make up 99% of everything a plant needs In its entire life the other 1% are all the micros.