New shoots turning yellow

bilbo,
Bummer man. Your water probably isn't the issue, especially of you leave it out for chlorine to evaporate. But if it were water or nute related...it wouldn't necessarily happen right away. Takes deficiencies (or excesses) awhile to develop sometimes.

Hey, as a test. You should do another run only hand-watering. I don't see how that alone could be the issue, but you say that's the only run that did ok.

Not familiar with the fungi-bomb but if the timing is right...that increases the possibilities. Did you use that on any of the other bad runs?
ET

Tryin to upload another photo here. Not working for some reason. Just says "uploading, please wait" for-fuqin-ever. Anyone else having problems uploading?

The new shoots have greened up, but I've got what looks like a P-def now.

Only used the fungi-bomb once, and haven't fired off anything since October. Doesn't make sense that this would still be causing me problems.

Ok, think it worked

Hey Hazy, did my PM go through? I either sent it 3 times, or not at all. Sorry. Still tryin to figure this thing out

Yeah i got em.
Potassium?

K gets slowed down by excess N, Sodium, Ca, Mg.
Keep that pH good , and maybe up the nutes?

Ok, so I'm still having the same potassium uptake problem, only for this run I've been using coco (Sunshine just coir) with recirculating nutrients on a flood and drain type deal. Same problem I've had with the last several runs regardless of the medium or nutrients. Though the problem seems to have been made worse by the use of coco as apposed to soil.

I went and had my water tested, and apparently they found high levels of calcium and magnesium. Please lemme know if I'm wrong here, but wouldn't this account for K being locked out. I bought a Small Boy water filter last week w/the carbon filter upgrade. Though FWIU, this filter's designed more for removing chlorine and sediment, not calcium and magnesium, if that is in fact what's giving me problems. Not sure whether I should get rid of the Small Boy and buy an RO, or perhaps keep the Small Boy and adjust my nutrients to have little to no calcium/magnesium.

Thanks, Bilbo