Please Help My Babies. Coco And Soft Water Issue? Potassium? Magnesium?

[gugulmale]

Hello everyone, really sorry if I end up posting this thread in a few different forums/sites but I could really do with help ASAP and the more opinions etc the better.
I am extremely desperate to not lose my babies as marijuana is genuinely what keeps me going for medicine reasons. If I lose this crop or have a poor yield then I will genuinely suffer as this is the only source of medicine I can get.



Firstly a bit of info.
My background tap water is extremely soft water, no it isnt softened, just comes out of the tap that way. EC 0.1. on my meter.
Checked with the water board also, they report 25ppm calcium and 2.5ppm magnesium, total water hardness 30ppm , so VERY low, especially magnesium right?


Plants are about 3rd week flower in CANNA COCO with COCO A+B, no additives. They always have shown yellowing between the veins around the low/middle of the plant however during flowering its more noticeable on the middle/upper part of the plant. The only way to overcome that is running a HIGH feed ec, around 1.8 or more.
I experimented with a few different brands of feed and still get the same problems. Even with soft water specific. Problems always show up in flower. At this same time the runoff EC starts drastically raising up so I have to drop it.

I am now getting serious problems with the edges of the middle leaves, and overall all the plants are a much lighter green or slightly yellow with yellowing between the veins. Leaves are dropping off easily on the lower branches.

I am not sure if there is an issue with magnesium deficiency or potassium deficiency or even potassium overdose. I tried adding epsom salts and calmag but havent seen much or any difference.

Temperature 25day / 20night , humidity 60% , VERY good circulation and ventilation. All 2.4mx1.2m tent with 1600w lighting not too close either.
Any ideas anyone? I am genuinely desperate here especially as they are in a super critical period of flower....

 

[ShroomKing]

You have a phosphorus deficiency.
And a couple deficient trace minerals.


Does not look to be caused by pH.

Best of luck.
Peace

 

[organix4207]

This phosphorus deficiency could be caused by over doing the calcium.

 

[gugulmale]

I havent really added calcium , only on one of the plants really. I have started adding epsom salts though and so far havent seen any results sadly.

Really appreciate your advice guys, would you say phosphorous is common deficient in coco? Its causing me a nightmare like.

 

[ShroomKing]

Phosphorus deficiency happens to us all.
Plants in flower can suddenly get very hungry for phosphorus.
You just have to adjust your feed, and be prepared on next run .

Best of luck.
Peace

 

[Seamaiden]

Looks more like a K problem to me. Mid-plant always reads as a K issue to me. All too easy to occur in coir. Although I see the blotchy thing that would also bring one to conclude P is at play here. But my experience with coir says that K should be addressed first, probably reduced is my guess.

 

[bobby.digital]

Based on your pics, your Ca and K levels are fine. Your girls are looking for P and Mg.

According to your feeding schedule in coco, P and Mg are likely present, just not available.

Are you sure you're letting that Ph swing high enough for that P and Mg coco sweet spot?

If so you might want to consider some sort of Ca + Mg supp and PK13/14 (or the bloom/bulk of your choice) regular supplementation schedule.

 

[bobby.digital]

A lot of this comes down to - you said you're in Canna Coco. Solid product not known for hogging Ca and K.

I agree with Sea and Shroom to the extent of P def. But am inclined to think that most of the rest is Mg. And overall possibly a low Ph issue.

 

[Rootbound]

Whats your run off ph?

 

[Herb Forester]

So far people have suggested every macronutrient deficiency without even asking how you water/fertigate :shifty::shifty: How exactly are you using that tap water, by itself ever? And how dry are you letting the coco get between waterings, times per day, etc.