Mystery issues with new growth

Hoping someone can assist with diagnosing the 'little leaf' issues I keep on running into.

First two pics are where it is more advanced - DWC.
Other two pics are different plants - coco, about to get a feed after letting medium dry out a bit.

Have seen on a few different plants, in different medium. Some times fix it, or fixes itself, sometimes progresses. Some times symptoms of zinc def show, some times potential iron def., other times no other symptoms other than the white-lime-green new growth that doesn't develop further.

Can add more info regarding nutes, etc. but have seen on wide variety of feed schedules and different mediums, so perhaps better to just show pics. Any help is appreciated

Sulphur.

polishpollack said:

Sulphur.

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Oooh, interesting, thanks m8. 100%?
I have always assumed veins yellow first with sulfur def.

Will use add some epsom salt, Mg boost will be good too.

Updating in case anyone experiences same.

90% sure this has been caused by excess calcium, but not 100% yet. polishpollack correct in Sulphur deficiency diagnosis.

However this is followed by further micro/trace nutrient def. on new growth, most likely manganese due to locations of necrosis, iron possibly as well but harder to distinguish due to sulphur def. Interestingly no real signs of potassium nor mag def. which are usually most commonly associated with excess calcium.

Sulphur is an often overlooked nutrient and there isn't as much information around that I can find. One source mentions a sulphur def. can on occasion be a precursor to lockout from excess calcium.

This would IMO explain the extreme stunting and yellowing/whitening of new growth as multiple nutrients are locked out.

Anynameiwish2 said:

Updating in case anyone experiences same.

90% sure this has been caused by excess calcium, but not 100% yet. polishpollack correct in Sulphur deficiency diagnosis.

However this is followed by further micro/trace nutrient def. on new growth, most likely manganese due to locations of necrosis, iron possibly as well but harder to distinguish due to sulphur def. Interestingly no real signs of potassium nor mag def. which are usually most commonly associated with excess calcium.

Sulphur is an often overlooked nutrient and there isn't as much information around that I can find. One source mentions a sulphur def. can on occasion be a precursor to lockout from excess calcium.

This would IMO explain the extreme stunting and yellowing/whitening of new growth as multiple nutrients are locked out.

Click to expand...

Soil growers who are not building a super soil should IMO water occasionally with a sea weed juice like Seasol. It contains a ton of trace elements. A shit load of em.

Looks like over fert caused a lock out.

Twerkle said:

Looks like over fert caused a lock out.

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Thanks m8.
I do wish it were that simple, but reducing feed (and cycling water, water, feed- for the coco) never helped and actually made bounce back take longer. Which is when started to consider excess Ca

Some waffling for explanation:
In DWC started to experience rapid pH drop a week or so after first made this thread, which was only resolved by eventually increasing feed strength, after decrease exacerbated pH drop (osmosis effect?) and girls in DWC bounced back quickly thereafter.

Sulphur def as first symptom reoccurred recently though, in DWC, changed res. immediately, changed again in less than 2 days after clearly getting worse, used 0.1EC water and hardwater nutes at same strength, bounced back real fast. Now real low Ca levels and just watching for any sign of Ca or Mg def. and will start supplementing in low amounts either with calmag or

Never SEEN any precipitate in res. mix in right order and dilute like a mofo before, assumed low Ca levels but if it is precipitating then it bonds with the sulphur to make gypsum? Sulphur def. explanation.

It all lines up quite well, as it is a recurring problem, showing up slightly differently in different mediums and 2 different strains - but still not 100%. I definitely will continue to consider overfert, thank you, sadly reductions haven't helped and often exacerbated the issue.