Yoz buddy! :smoking: ..been seeing some odd shit lately, and yours is no exception,... first round of pics had me wondering some, but the new ones confirm-- this is Ca defc.! But that said, the tight vein yellowing pattern on those first pics is the oddest symptom set I've seen for Ca defc.,.... it's common for some symptoms of Ca defc. to form up along the veins, but like this, in your case, it's a first for me! Here's a pic that shows a similar pattern, but not nearly as marked as you plant-->
>>> this is more typical->
...as are the pics in the CM XL above,... One thing to keep in mind with many defc./toxicity symptoms, is that they don't always manifest in the typical pattern; other factors can change how they appear, including other co-defc.'s, hydro vs. soil vs coco, toxicity issues, lockouts, etc. etc.,... diagnostics can be a real bitch sometimes!
.... so, you know what I'm gonna ask next, right? -soil pH! Ca isn't real fond of overly acidic pH, but it locks out slow, and it has to be pretty damn acidic too, so maybe this is more of a lack-of, than a pH lockout issue...(get me a proper reading anyway please),... as for the hard water, it might be great for buffering, but if it's pretty alkaline, I think the Ca stays more locked up in the CaCO3 form, vs the ionic Ca++ form, and as such, isn't available for uptake in that form by the plant, so even if it's present, it's not absorbable,... can you get RO/DI water Yoz? Blending would really help with things, getting the ppm's down... do you know what ppm's or EC the tap is at? meantime, get on the Ca-Mg at full power,... to bad you're in bloom, or a foliar spray would be the fastest, best way to hammer this out,.. problem is, Ca is nearly immobile within the plant, so it can't tap into other older leaves for it,... do you have a wetting agent? ...you still could, with some guidance and careful, sniper-shooting of the spray to minimize overspray onto the buds and focus on the fans only,... soil treatment will take a few days to really start affecting, so expect some progression to continue,.. and of course, Ca defc. symptoms don't reverse,... Oh-- also noted, and maybe it's just the camera/pics, but the plants look rather deep green, a minor sign of N-toxicity, which can mess with Ca uptake as well,...
