Gray & white spots on auto in Tupur mix: pH flux?

[Cwmoore577]

It’s a Zkittlez autoflower in Royal Gold Tupur mix. Tent is always 70-71°F and 50-55% RH. I feed twice a day with 8-10ml/gal of General Organics BioThrive Grow (NPK 4-3-3) and 4-5ml/gal of Emerald Forest CalMag (NPK 2-0-0). I pH to 5.8-5.9 with CES pH Up. I measure the EC and TDS and have been feeding EC around 900-1000 and PPM of 600-700.

Thought it could be cal issue so I gave a few foliar feedings of calmag water (4ml/gal). The spots are gray-ish and color and also there are white spots so I thought it might be pH?

I measured my runoff and pH is high at 6.7-6.8. EC was around 1050.
Last two days I’ve lowered the EC I feed and have started watering 3x daily instead of 2x.

I gave two gallons last night to flush the pH down at 5.5pH, EC 630 and 425 ppm. Got the pH down to 6.3.
Watered this morning with pH 5.5, EC 590 and 400ppm and the runoff pH was back to 6.7.

A lot of what I’ve read says to ignore runoff pH but I’m not sure what else to do. The spots keep progressing.
Any help or advice really appreciated!!

 

[Old Salt]

to the forum...

It does look like a cal/mag deficiency. Has it progressed since you treated it? Once the leaves are damaged, they generally don't recover. You need to look to see if it's getting worse.

 

[Emilya Green]

You are having a deficiency, but I think it is pH related and not based on you not supplying the needed nutrients. Your medium is NOT a soil... it is a soilless coco mix and therefore it needs to be run as a coco/hydro operation with your pH adjusted down into the hydro range of 5.5-6.1 With your pH where you are adjusting it, many things are not going to be mobile in that mix, especially magnesium, and it is no wonder you are not getting it to go up into your plants even though you are providing it.
Do nothing else other than adjust your pH to the correct range, I suggest shooting for 5.8 pH. Doing so I believe is going to clear up all of your troubles without adjusting anything else.

 

[Emilya Green]

oh, and runoff pH does matter and is important in a coco based grow. It is only in soil based grows where runoff pH is meaningless.

 

[Cwmoore577]

to the forum...

It does look like a cal/mag deficiency. Has it progressed since you treated it? Once the leaves are damaged, they generally don't recover. You need to look to see if it's getting worse.

It has progressed a lot. I’ve given about 6-7 foliar feeds of calmag water along with the normal dose of calmag in the 2 weeks since I’ve noticed the spots, thinking that it was a cal issue. Not sure what to do as it’s not working, yet anyways.

You are having a deficiency, but I think it is pH related and not based on you not supplying the needed nutrients. Your medium is NOT a soil... it is a soilless coco mix and therefore it needs to be run as a coco/hydro operation with your pH adjusted down into the hydro range of 5.5-6.1 With your pH where you are adjusting it, many things are not going to be mobile in that mix, especially magnesium, and it is no wonder you are not getting it to go up into your plants even though you are providing it.
Do nothing else other than adjust your pH to the correct range, I suggest shooting for 5.8 pH. Doing so I believe is going to clear up all of your troubles without adjusting anything else.

I said in the post that everything is pH’d at 5.7-5.9. Mostly right at 5.8 except for trying to flush it last night with pH of 5.55. This is my first attempt in coco, but I’ve done all the research and have read cocoforcannabis.com extensively.

I’m not sure if there’s something in the BioThrive nutrient line causing pH to rise but it says on their site it can be used in coco.

 

[Emilya Green]

I said in the post that everything is pH’d at 5.7-5.9. Mostly right at 5.8. This is my first attempt in coco, but I’ve done all the research and have used cocoforcannabis.com

sorry... you did indeed. I was keying in on the pH numbers you were saying your runoff was giving you and I gave you an undeserved lecture. Please forgive me, I was actually a little distracted at work and was mutlitasking, obviously not quite so well. Ok, so you have 5.7 going in, much higher coming out... that should tell you something. Have you flushed your medium recently?

 

[Cwmoore577]

sorry... you did indeed. I was keying in on the pH numbers you were saying your runoff was giving you and I gave you an undeserved lecture. Please forgive me, I was actually a little distracted at work and was mutlitasking, obviously not quite so well. Ok, so you have 5.7 going in, much higher coming out... that should tell you something. Have you flushed your medium recently?

No problem. I had not flushed until last night I gave it two gallons of a lighter mix at an EC of 600 and pH of 5.5 trying to lower the runoff pH and got it down to around 6.3.
Watered it again this morning and checked runoff and it was back up to 6.7

 

[Emilya Green]

I went back to the internet to see what I could find about that mix and I ran into this:
Royal Gold Tupur, pronounced (two-per), was designed with the idea feeding your plant as much and often as possible. It is a blank slate to create your own high performance feeding regimen. As a coco fiber based soilless medium, it requires high levels of calcium and magnesium to unlock its true potential.

The deficiency thing is no more complicated than this. They have described your problem. Up the calmag rate, to its max.

As far as the pH thing goes, I am perplexed and am waiting for a real coco expert to show up here and tell us what is going on. I am guessing that since this stuff is designed to let you feed up to 6 times a day, that it has a very fast upward drift rate built into it, and whatever buffers are in it to cause this to happen are showing up in your runoff. I am just guessing though and really have no idea what it could be.

 

[Old Salt]

The pH and EC/TDS of the run off change dramatically if you don't get enough run off for a period of time. You get many of the same symptoms as a soil grow with nutrient/water lockout. I've only done it once to myself. Following Emilya's grows led me to suspect this in my own grow.

I corrected this by feeding my normal nutrient solution to 50% run off for two or three days. I'll mention that with most of the nutrient lines, you need to use less than 50% of what the manufacturer recommends. For me with General Hydroponics' Flora Trio it was only 35% of what was on the labels. When I went to 40% my plants got nutrient burn. Cal/mag was the only component that had to be increased to 45%. With the all-in-one Mega Crop, I need to add a little extra cal/mag as well.

 

[Cwmoore577]

I went back to the internet to see what I could find about that mix and I ran into this:
Royal Gold Tupur, pronounced (two-per), was designed with the idea feeding your plant as much and often as possible. It is a blank slate to create your own high performance feeding regimen. As a coco fiber based soilless medium, it requires high levels of calcium and magnesium to unlock its true potential.

The deficiency thing is no more complicated than this. They have described your problem. Up the calmag rate, to its max.

As far as the pH thing goes, I am perplexed and am waiting for a real coco expert to show up here and tell us what is going on. I am guessing that since this stuff is designed to let you feed up to 6 times a day, that it has a very fast upward drift rate built into it, and whatever buffers are in it to cause this to happen are showing up in your runoff. I am just guessing though and really have no idea what it could be.

Thank you so much for your time and help. I very much appreciate it. So I’d imagine watering 3x daily would help a bit? Also when you say calmag to the max, should I go over the bottle recommended 5ml/gal? That’s what I’ve been giving so far.

The pH and EC/TDS of the run off change dramatically if you don't get enough run off for a period of time. You get many of the same symptoms as a soil grow with nutrient/water lockout. I've only done it once to myself. Following Emilya's grows led me to suspect this in my own grow.

I corrected this by feeding my normal nutrient solution to 50% run off for two or three days. I'll mention that with most of the nutrient lines, you need to use less than 50% of what the manufacturer recommends. For me with General Hydroponics' Flora Trio it was only 35% of what was on the labels. When I went to 40% my plants got nutrient burn. Cal/mag was the only component that had to be increased to 45%. With the all-in-one Mega Crop, I need to add a little extra cal/mag as well.

I’ll increase my runoff and see if that helps.

 

[Emilya Green]

So I’d imagine watering 3x daily would help a bit? Also when you say calmag to the max, should I go over the bottle recommended 5ml/gal? That’s what I’ve been giving so far.

Yes, this is a designer medium designed to let you feed it as often and with as many nutes as possible... that is their stated claim to fame. So to accomplish this, they have to be performing some sort of magic and I think you hit on their secret... very fast upward drift. So work with it... and yes, 3x a day sounds like the ticket... more if you want... just keep it coming at them like it was a drip feed hydro. And this is some special mix of coco too, and they say it needs high levels of not just magnesium and calcium but they warn that the coconut coco will leach out potassium... so you have to be careful not to overload your mix with that. You will run the balance between a potassium overload and a calcium underload in this grow... but now you know what to look for. Those little spots are nothing... just the start of the deficiency, so you are right on the edge. Lets see if the multiple feedings gets what is needed in there before you raise the levels. Use the stuff as designed, dance with the one who brought ya.

 

[Cwmoore577]

Yes, this is a designer medium designed to let you feed it as often and with as many nutes as possible... that is their stated claim to fame. So to accomplish this, they have to be performing some sort of magic and I think you hit on their secret... very fast upward drift. So work with it... and yes, 3x a day sounds like the ticket... more if you want... just keep it coming at them like it was a drip feed hydro. And this is some special mix of coco too, and they say it needs high levels of not just magnesium and calcium but they warn that the coconut coco will leach out potassium... so you have to be careful not to overload your mix with that. You will run the balance between a potassium overload and a calcium underload in this grow... but now you know what to look for. Those little spots are nothing... just the start of the deficiency, so you are right on the edge. Lets see if the multiple feedings gets what is needed in there before you raise the levels. Use the stuff as designed, dance with the one who brought ya.

Did not know that either. Wonder if the Biothrive Bloom will be ok for it. It’s 2-4-4.

Also if it means anything I’ve now noticed a few purple stems.

 

[Emilya Green]

Did not know that either. Wonder if the Biothrive Bloom will be ok for it. It’s 2-4-4.

Also if it means anything I’ve now noticed a few purple stems.

the Biothrive should be fine... mind the potassium warning and go lightly, but go often. Keep heavily supplementing calcium and magnesium. The red and purple stems can be indications of stress, and this coloration is one of the mechanisms that the plants use to move around... it is not always a warning that something that needs to be heeded .

 

[Cwmoore577]

the Biothrive should be fine... mind the potassium warning and go lightly, but go often. Keep heavily supplementing calcium and magnesium. The red and purple stems can be indications of stress, and this coloration is one of the mechanisms that the plants use to move around... it is not always a warning that something that needs to be heeded .

Ok will do. I switched to tap water instead of RO, kicked the calmag up to 6ml/gal and dropped the biothrive to 4ml/gal. EC is around 600-700 and 450-500 ppm.

Does that sound alright?

 

[Emilya Green]

Ok will do. I switched to tap water instead of RO, kicked the calmag up to 6ml/gal and dropped the biothrive to 4ml/gal. EC is around 600-700 and 450-500 ppm.

Does that sound alright?

just what I would have done... lets see what happens.

 

[Cwmoore577]

just what I would have done... lets see what happens.

Just to update. Ive been using tap water (usually EC around 150) with about 4-5ml/gal of calmag and 4ml/gal of biothrive grow 3x a day instead of two. EC has been 600 to 700 range, ppm 400 range.

I defoliate most of the leaves that had the spotting so I could see if it’s progressing. My runoff pH has lowered to lows 6’s. Usually 6.1-6.3. EC has been around the same of my inflow every time.

Spots still progressing but at a much slower rate. Also still seeing some purple stems, lighter green colored new growth and stems seem to sag.

I’ve also added a new light to the tent since this post. It’s a SunSystem HPS 150 to go with the cheap 100w output blurple led that was already in there. Unsure if they would have any effect on the symptoms.

Here are some pictures

@Old Salt

 

[Emilya Green]

 

[Cwmoore577]

Could too much calmag lock it out? I can’t seem to figure out why it’s still getting worse while using tap water with 4ml/gal calmag and also doing foliar feeds with calmag water.

 

[Emilya Green]

Could too much calmag lock it out? I can’t seem to figure out why it’s still getting worse while using tap water with 4ml/gal calmag and also doing foliar feeds with calmag water.

I think your problems are pH related... not the levels of magnesium. You probably need to experiment with some different values and see what that Tupur best likes you to come in at... apparently what you are using now is not the right setting.

 

[Cwmoore577]

I think your problems are pH related... not the levels of magnesium. You probably need to experiment with some different values and see what that Tupur best likes you to come in at... apparently what you are using now is not the right setting.

So maybe raise it a bit for better calmag availability? I’ll try around 6.0