Seedling in rockwool. Light green leaf margins.

Probably locking some things out.. go to 5.8-6. i prefer 6. it gives room for error in each direction. the overall balnce of nutes is possibly off too.. not enough info on that. You need concentration of each molecule to udnerstand that.. not ec of his product or that. that varies greatly and doesn't communciate much to others. you can learn an esoteric familiarity from it and that is useful in your particular garden but to others it is greek. in hydro ppm suggestions.. 120-130 N 40-60 P 180-200 K 100+ Ca 50-75 Mg 100+ S Your water may have Mg or Ca in it as well as some other things, so some trial and error locally is needed, but this is a solid starting point to compare to... anything drasticalyl off might be causing a tox/def/lockout. the thing about fertilization is you don't learn if oyu formula is solid until you apply it for a long period of time.. small imbalances will take a month or more to show an issue. some nutes, like Mg, don't show a visible symptom until 4-6 weeks AFTER onset of the problem.. so when you see an Mg deficiency, it started over a month ago, and that's the timeframe you need to assess to correct it. just as a target DLI, this requires a little "observe and adjust" on your part. Local variables make for slightly different needs. But, if you look up the hydro products based on real research and not some guy's formula that ignored existing knoweldge, you find the resulting ratio of nutes are similar to this... whether jacks hydro, souther ag hydro, athena proline, masterblend's hydro trio.. etc etc.. they all come out to a similar set of PPMS.. some are a bit higher or lower overall concentration. e.g. jacks instructs for soemthign like 140-150ppm N and that's almost certainly going to cause a buildup over time. it migh be fine for a short 1-2 week stretch but eventually it'll be a problem for a potted plant.. outside with plants in the earth, it's an awesome concentration. the point is all the products don't come to this basic ratio and concentration whimsically.. there's generational knowledge behind it. they are basing their products of the same knowledge... with very slight differences primarily just to make them look like they might have a better option, but it's really quite whimsical in nature.

Probably locking some things out.. go to 5.8-6. i prefer 6. it gives room for error in each direction. the overall balnce of nutes is possibly off too.. not enough info on that. You need concentration of each molecule to udnerstand that.. not ec of his product or that. that varies greatly and doesn't communciate much to others. you can learn an esoteric familiarity from it and that is useful in your particular garden but to others it is greek. in hydro ppm suggestions.. 120-130 N 40-60 P 180-200 K 100+ Ca 50-75 Mg 100+ S Your water may have Mg or Ca in it as well as some other things, so some trial and error locally is needed, but this is a solid starting point to compare to... anything drasticalyl off might be causing a tox/def/lockout. the thing about fertilization is you don't learn if oyu formula is solid until you apply it for a long period of time.. small imbalances will take a month or more to show an issue. some nutes, like Mg, don't show a visible symptom until 4-6 weeks AFTER onset of the problem.. so when you see an Mg deficiency, it started over a month ago, and that's the timeframe you need to assess to correct it. just as a target DLI, this requires a little "observe and adjust" on your part. Local variables make for slightly different needs. But, if you look up the hydro products based on real research and not some guy's formula that ignored existing knoweldge, you find the resulting ratio of nutes are similar to this... whether jacks hydro, souther ag hydro, athena proline, masterblend's hydro trio.. etc etc.. they all come out to a similar set of PPMS.. some are a bit higher or lower overall concentration. e.g. jacks instructs for soemthign like 140-150ppm N and that's almost certainly going to cause a buildup over time. it migh be fine for a short 1-2 week stretch but eventually it'll be a problem for a potted plant.. outside with plants in the earth, it's an awesome concentration. the point is all the products don't come to this basic ratio and concentration whimsically.. there's generational knowledge behind it. they are basing their products of the same knowledge... with very slight differences primarily just to make them look like they might have a better option, but it's really quite whimsical in nature.

The ph should be where you have it to about 5.8. I prefer closer to 5.8. This needs to be the ph after it passes through the rock wool. You are doing various soiless or Hydro grow. So Hydro rules apply. I am guessing the run off ph isn't right and that may cause a lot of your issues. Since this will be a ph sensitive grow.

Your pH is way too low and affecting nutrient availability. Somewhere around 6.2 - 6.4 would be better.

Hey don't think the problem is the solution here as you say. From experience that shading starts with ph fluctuation. Rockwool cubes have a ph of almost 8. Did you make sure to adjust their ph before ?