Burn? Deficiency? Hydroponic fgrow

I think you have concurrent problems - more than 1 at same time. Possibly low P or lockout. Ca and Fe levels can lockout out P. (see: Mulder's Chart). I really doubt Fe is high, but it is no unusual for people to overdose Ca. Probably only need 100+ ppm of Ca. If way over that, definitely possible. I feed at ~100ppm but i probably get a few ppm from my water, but not much since i switched to soft water (lol, yeah i know, but it works fine for only 100 days in a pot) 1.8 EC is a bit high if it is all fertilizer. If you are also getting .4-.6 of that EC from your tap water, it is fine. If it is all fertilizer, lower doses to 1.3-1.5EC is all you need and that will mostly depend on your VPD (This 1.3-1.5EC does not include ppm from tap water, fertilizer-added only) Calculate from guarnateed analysis labels and dose given. Hydro Buddy is a free app that can do this , i believe. can google for other options or make a spreadsheet that does it for you. Try running at 6.0 pH. It gives more leeway for error and i doubt you can see any difference with the naked eye when it comes to a handful of plants. Genetic variation alone is too much fog of war to discern anything like that. I know, people have a hankering for being nazis about 5.8 in dwc, but it's silly and of no consequence by comparison. All it does is make you feed more Ca than necessary as you get closer to lockingn Ca out with pH. Lucas formula is not as good as advertised. Go with the formula used by numerous professional Ag companies that pre-date the efforts of marijuana brands that obstinately ignore existing knowledge bases. So many uneccessary repeated mistakes due to this. Look up jr peters, masterblend, souther Ag brands, etc.. there are many that use a very similar formula once mixed (despite slight variations to base product) because it's based on existing research of sample sizes that far exceed whatever 'lucas' did.. whoever that is, i don't keep up with pot subculture, lol. Usually a based fertilizer + calcium nitrate + epsom if needed. But, an app like hydobuddy can take just about any hydro fertilizer and calculate a similar formula from the guarnateed analysis labels. Enter target ppms and info from labels and it will poop out the dosage that gets close enough. N 120-130 (maybe 100-110 once stem elongation and leaves stop growing) P 40-60 K 180-200 Ca 100+ Mg 75ish S 100+ Local variables, including water used and vpd, will impact what is best. These are ballpark numbers. if your bottles of nutes are 5-10% off on any one value (when mixed) but mostly are similar, all is well. From there you can observe and adjust and i guarantee you'd never see a mess like this... never. Very easy to diagnose symptoms if any and so slow moving you have all the time in the world to react. Within 1-2 cycles you'll have a formula that works with 99% of plants you grow. I use this formula growing 7+ strains all pulling from the same rez and rarely see symptoms. I run a higher vpd due to cost, not on purpose. This will be near low-end of overall concentration. IF VPD is high, the plant drinks more per day and you need a lower concentration. IF VPD is lower, you need more than me because your plants don't drink as much water per day. The goal is providing the same mass of nutes per day that match up growth rate. To be clear i speak of what enters the plant as far as mass = growth and not the formula itself in this context - nutrient uptake is about maintaining critical levels of all nutes around the roots at all times... The optimal ratios of nutes around the roots are not in proportion to how they will be used, despite common belief. That was my first extrapolation before i learned better. It is about availability and not locking each other out, as well as a consistent and slightly acidic pH. Being able to actively 'grab' p and k unimpeded is an important goal. if it all just entered the plant with water, then we would feed in proportion to use/growth, but 70-80% of p and k and smaller portions of other things do not enter the plant this way. They are actively transported by specific proteins that will only bond to specific nutrient molecules -- concentration gradients cause them to diffuse back into roots. The release of these proteins outside the root are controlled by the plant. It grabs what it needs in this case, unlike what enters through 'mass flow'