coco and yes, brown spots

[searchingforit]

I've searched through the infirmary and have seen a few cases of this which look identical. There was no 100% conclusion. Some said "for sure" cal/mg (but which one?), others said this is burning, others said no idea. I did hit these two problem plants with calimagic but the progression continues.

These are in canna coco. pH about 6.0. Each feed works to about 700ppm consisting of:

N 129
P 52
K 102
Ca 129
Mg 43
S 45

Only 2 of my plants are displaying this. It is towards the bottom, more like the middle of the plant. Not the very new growth. It starts off as a few spots towards the end of the leaf tip then creeps inward over a few days. No scorched tips/edges. Here are some pictures:

 

[stoned40yrs]

P lockout. You should never use calimagic unless you are using RO water. We talk in ec here because there are 2 scales and we don't know which you use. I assume you are talking 500 scale so your 700ppm is 1.4ec. That's too high for tiny plants, back your feed down to 500ppm or 1.0ec. Run this 1.0ec as a flush a couple times a day for awhile and make sure your ph is correct. That coco looks too dry also. If you have some good roots on those keep that coco moist.

 

[searchingforit]

Yes, that is 1.4 ec. My tap is 18 calcium 3 mg so fairly negligible. I will back down to 1.0ec and see results. My other plants look good, 2 are displaying this. And you're right on the dryness of the coco.

 

[stoned40yrs]

Calmag overdose or bad ph or too dry of coco is responsible for locking out P like you have most of the time. Keep those in check and you won't get leaves like that.

 

[Acquitted]

I've gotten brown spots on my flowering plants but not others and about half show the same with my vegging plants. I had varying pH but nothing close to what would be considered detrimental, and over watering was definitely not an issue. I added Epsom salt and spring water solution to their next watering and they are doing great. No more brown spots showing and it may be my imagination but I think they look more vibrant

 

[searchingforit]

Problem seems to have halted. All other small plants doing great.

 

[searchingforit]

Spoke too soon. Yesterday I noticed a plant with a middle leaf discolored/fading. Today it has those marks on it. What I am also noticing is new growth has scorched yellow tips. Now really, I am feeding between 400-500 ppm of base nutes. I don't allow the coco to dry out. When I was feeding heavier I wasn't seeing these scorched tips. My roots are explosive and healthy. pH going in is 5.8. General plant health looks good but I keep seeing this leaf damage and now the scorced yellow tips.

 

[stoned40yrs]

We talk ec here 500 scale. So you have good roots. Are you sure your ph pen is good and accurate? I double check with GH drops. Bump up the feed to 1.1ec, 6.0ph and feed these plants 2 or 3 times a day with runoff for a week, you have good roots, it will like multiple feeds with runoff. Watch the top 1/3 of the plant/new growth. It will pull out of the problem. Forget the bottom leaves that will be an old problem soon.

 

[searchingforit]

Yes, my ec is 1.4 going in which includes .4 ec tap. Therefore 1.0 ec basenutes. I lowered that to .9 EC basenutes during my first post. After that, the progression of the black/brown spots did seem to halt, however that yellow scorch on the new growth tips began. Even at .9 ec base nutes I am getting the scorch on all new growth. I am moving these to hempy buckets tomorrow.

 

[searchingforit]

Also, I have a very good pH pen that is calibrated and drops to confirm my input. Using the bluelab truncheon for EC.

 

[searchingforit]

What's your opinion of the scored tips at the top? It seems the new brances of sidegrowth are not exhibiting this yellowing at the tips, only the new growth on the very top. I find it hard to believe 1.0 ec of nutes is causing tip burn as these are getting bigger.

 

[searchingforit]

 

[stoned40yrs]

1.4ec is too high IMO. Even in bloom I never go above 1.3ec. You don't add the desired ec on top of the waters ec. It's the waters .4 ec and then .6 of the nutes to get 1.0ec. not 1.0ec of nutes and .4 water to get 1.0ec. Have you scoped the underside of the leaves for bugs. What is going to be in your hempy- straight perlite? At least going into the hempy will eliminate the coco causing the problem. This isn't a huge problem that will effect the final product. Plenty of time to figure it out.

 

[searchingforit]

I am not familiar with counting tap pph when calculating nutrients. For instance my tap is 180ish ppm or a little over .3 EC. The water test reveals approx. 20 ppm calcium, 5 ppm Mg, single digit or lower K, copper, iron, sulfur. The rest of that is sodium, chlorides and so fourth. Therefore 40 ppm or less of my tap is anything the plant will be using. When you suggest 1.0 EC (500 ppm) to aid in my problem, if I included tap ppm into that I would be feeding at 300 of plant available nutrients.

No bugs on the plant. And my hempy will be 100% coco with perlite on the bottom.

I am going to continue to tinker around before I flower as I believe they are on the cusp of greatness. The roots are the best I've had on plants these size. I will also say I am using DM gold and experimenting to see if that might be affecting things.

 

[Loc Dog]

You have scanned several sick leaves with a microscope?? Just want to make sure you realize mites are barely visible with microscope. Check bottoms of leaves first, then tops.

 

[maimunji]

I have exactly same problem my previous 2 grows with my fastest growing plants. Yellow tips at new grow. Blotchy spots with some brown, yellow at big fan leaves on upper side of plants. I believe its some kind of micro deficiency because always dissappear when I add cal mag full dose. I try everything. When I flush plants getting worse and yellow tips progress to two rusty spot on both aide of leaves tips.

 

[maimunji]

 

[Loc Dog]

[URL=https://www.icmag.com/ic/picture.php?albumid=60688&pictureid=1588020&thumb=1]View Image[/url] [URL=https://www.icmag.com/ic/picture.php?albumid=60688&pictureid=1457440&thumb=1]View Image[/url] [URL=https://www.icmag.com/ic/picture.php?albumid=60688&pictureid=1455005&thumb=1]View Image[/url] [URL=https://www.icmag.com/ic/picture.php?albumid=60688&pictureid=1455006&thumb=1]View Image[/url] [URL=https://www.icmag.com/ic/picture.php?albumid=60688&pictureid=1454366&thumb=1]View Image[/url] I have exactly same problem my previous 2 grows with my fastest growing plants. Yellow tips at new grow. Blotchy spots with some brown, yellow at big fan leaves on upper side of plants. I believe its some kind of micro deficiency because always dissappear when I add cal mag full dose. I try everything. When I flush plants getting worse and yellow tips progress to two rusty spot on both aide of leaves tips.

This is the best guide for sick plants that I have seen. Skim through it quickly, looking at the pictures, to see if it matches yours. It is a great read, when you have time to go through the whole thing. I starts with macro nutrients, then moves onto micro nutrients.

https://www.icmag.com/ic/showthread.php?t=11688

 

[searchingforit]

[URL=https://www.icmag.com/ic/picture.php?albumid=60688&pictureid=1449181&thumb=1]View Image[/url]

Now in this case, that looks like overfert.

 

[searchingforit]

This is an overferted plant which looks similar to yours.