Mag deficiency, or overwatered coco?

[Kazooey59]

If the Canna regimen presumes use of unbuffered coco but your coco is pre-buffered or pre-loaded with Ca/Mg, could you be overdosing Ca and/or Mg?

With the adverse effects limited to "just the Acid Snow strains that have these weird symptoms" and you presumably doing everything right, as you note the problem could just be the strain and/or that specific batch of seeds.

I imagine you have to use calmag one way or another, or? If you use unbuffered straight out the bag, you probably have to use even more calmag, but with RO water you're hitting zero on EC, which is why you always have to add calmag first as a stabilizing agent in the otherwise empty water, or PH will go absolutely crazy. You generally wanna start with a 0.3-0.4EC base and then add the Canna nutrients, as recommended by Canna. My reverse osmosis water has 0.0EC, so I have to add the base first, which is calmag

 

[BII]

I imagine you have to use calmag one way or another, or? If you use unbuffered straight out the bag, you probably have to use even more calmag, but with RO water you're hitting zero on EC, which is why you always have to add calmag first as a stabilizing agent in the otherwise empty water, or PH will go absolutely crazy. You generally wanna start with a 0.3-0.4EC base and then add the Canna nutrients, as recommended by Canna. My reverse osmosis water has 0.0EC, so I have to add the base first, which is calmag

I don't agree that "you always have to add calmag first [to RO water] as a stabilizing agent in the otherwise empty water;" "have to add the base first, which is calmag;" and "have to use calmag one way or another." You seem to be mixing up cal-mag supplementation and pH "stabilization" [what does that refer to?] issues. What's wrong with starting with 0 ppm water (other than your pH sensor readings will be very unstable/unreliable with near nothing to measure; Is that what you seek to "stabilize" by adding salts); and then following manufacturer mixing recommendations and only adding Ca/Mg as needed?

You don't need to always upfront adulterate your water with Ca, Mg or any other "buffering agents" (salts) if these are not needed by the plants or media. Your base nutrients should be able to "stabilize" ultra-low pH water (give the meter some ions to measure).

Regarding your plants: Do the Canna recommendations presume the coco being used is not pre-buffered (and needs Ca/Mg supplementation with their base nutes)? Is your coco pre-buffered/treated or not? Your cal-mag supplementation should take this into account. For ex., Canna coco is pre-buffered rather well. I use it right out of the bag, with no pre-use cal-mag dosing or rinsing, and don't add cal-mag (maybe once per grow) using RO water with MegaCrop 2-part.

If you think it's a Mg deficiency, consider foliar feeding with MgSO4 (epsom salts) or a cal-mag product (and avoid adding more salts to your feed and media).

 

[Kazooey59]

I don't agree that "you always have to add calmag first [to RO water] as a stabilizing agent in the otherwise empty water;" "have to add the base first, which is calmag;" and "have to use calmag one way or another." You seem to be mixing up cal-mag supplementation and pH "stabilization" [what does that refer to?] issues. What's wrong with starting with 0 ppm water (other than your pH sensor readings will be very unstable/unreliable with near nothing to measure; Is that what you seek to "stabilize" by adding salts); and then following manufacturer mixing recommendations and only adding Ca/Mg as needed?

You don't need to always upfront adulterate your water with Ca, Mg or any other "buffering agents" (salts) if these are not needed by the plants or media. Your base nutrients should be able to "stabilize" ultra-low pH water (give the meter some ions to measure).

Regarding your plants: Do the Canna recommendations presume the coco being used is not pre-buffered (and needs Ca/Mg supplementation with their base nutes)? Is your coco pre-buffered/treated or not? Your cal-mag supplementation should take this into account. For ex., Canna coco is pre-buffered rather well. I use it right out of the bag, with no pre-use cal-mag dosing or rinsing, and don't add cal-mag (maybe once per grow) using RO water with MegaCrop 2-part.

If you think it's a Mg deficiency, consider foliar feeding with MgSO4 (epsom salts) or a cal-mag product (and avoid adding more salts to your feed and media).

Hey BII,

So I've contacted Canna just to make sure, but it'll probably take a few days until they answer, so I don't really have an official statement from their side. I did search through the internet though, and found this (Source: Reddit)

"I used ro before (0.0)ec with no cal mag and had deficiencies. I contacted canna & they recommended adjusting tap to 0.4 then add my nutrients exactly like the canna grow guide says. I have had no deficiency since doing this it’s been 3 years."

He mentions tap though, which confuses me again, even though he started with RO water.

My coco is pre-buffered and washed, correct. It's ready to use right out of the bag. I just read everywhere that RO water should always be re-mineralized with calmag first, which is what I then ran with.

Canna recommends a starting EC of 0.4 with their nutrient line, as mentioned in their Grow Guide, so I feel like it is correct to add Calmag until 0.4, but once again I'm unsure now. My plants also keep looking worse and worse now, it's still only the two specific strains that do this, but it doesn't seem strain-related, it really seems to be something with a deficiency or lockout. Problem is - I've never seen something like this. I know pretty much all the deficiencies as I really went through a ton of problems back then, but this one is totally new to me.

 

[BII]

There are multiple issues you are mixing together here - Mg (and Ca) supplementation of feed water, water "stabilization" (still don't know what that is; is it getting a stable starting pH reading; is this some type of 'bro science' or what?), coco being properly (pre-)buffered, and routine feed pH adjustment.

What to do could be simple: I suggest just follow the nutrient manufacturer's instructions and from there treat the presumed problem with these few plants. If it's Mg deficiency, do foliar treatment with epsom salts (ideally with Transport) and avoid adding more salts to your feed water. Or since the other plants are doing fine, just hope the problem plants grow out of this phase and cull them if they don't.

 

[Lil Dab]

This is what I ws taught by @Mañ'O'Green which I trust wholeheartedly plus I've been doing it for a while now and my plants are better. I like tothink there little more to it then just "bro science"


The history of why I invented stabilizing RO. When I first started using RO It did all manor of weird PH shit to my reservoir when I added it to bring the PPM down in a nutrient mix to the range I wanted. I used RO because it added only water to the mix. But it took copious amounts of up or down to keep PH in range. You know that PH+ Nitric Acid adds nitrogen, PH+ Phosphoric Acid adds Phosphorus to your nutrient mix. When you use large amounts it will change your nutrient balance. Keep in mind I am in hydro and my PPMs would change by as much as 75PPM. This was not desirable. Then I learned that RO water is hungry and will pull Co² out of the air and drop the PH to 5.5 or lower. I read somewhere that adding some base ions would mitigate this action. It can be any metal ion. I started adding a little cal-mag to the RO and Bota Boom Bota Bang it stop hijacking my reservoir PH. Then I discovered that everything mixed better without any precipitation I could see if I used this "buffered" RO. The reason I used 50 PPM of Cal_mag was because that was the lowest number my EC pen could read. Not all Cal_mags are made the same but most are calcium nitrate and Mg nitrate and maybe some iron once again a source of Nitrogen I don't want. Hence my choice of Soluble Gypsum which is Ca and Sulfur, Epsom Salt is Mg and Sulfur. Cannabis can tolerate a lot of Sulfur way more than you are likely to get in any nutrient line. I settled on .3g Soluble Gypsum and .3g Ag Epsom Salt per gallon of RO that gets me close to that 50PPM mark that most meters can read. It works well for me so I teach it.

 

[Lil Dab]

Hey guys,

So I'm currently running some imported Speedrunseeds genetics, it took a full month to arrive, so I'd be sad if these just straight up die.

I'm running coco/perlite 60/40, solo cups, Canna Coco nutrients + Canna Calmag Agent, RO water. I add Calmag until I'm at 200PPM / 0.4EC, and then Canna Coco A+B until I'm at 1.6EC currently. PHed to 5.8. They also get the full 1.6EC as two fertigations per day, always til runoff (around 30-40ml per fertigation, with a syringe). Temps are at 80-82°F, humidity always around 65-70%. They will soon be transplanted into autopots. I have one already in an autopot, just without the system turned on, she is 100% fine, just a few days older.

It's apparently just the two "Acid Snow" seeds from Speedrun that show problems. The other two Granite Haze F5 are fine, one being the older plant. They all seem to take up the multiple fertigations just fine, but now I feel like something actually might be wrong with the two. It looks like a magnesium deficiency to me personally.

I did some tests, checked runoff EC and PH. Runoff EC was 0.1 higher than input, which is fine I think. Runoff PH came out at 5.6 though, which seems a bit low? I tried fixing this by finally varying in the PH input I use, as I always went for 5.7-5.8PH, rather than going a bit more upwards sometimes. I now fed them with 5.9-6.1PH as of yesterday where I noticed these problems, but I don't know if this will actually fix it, if that's even the cause of these problems. PH runoff is now at around 5.8-5.9

View attachment 1689700View attachment 1689701

Some people said that I'm straight up overwatering, because of the algae growth. But I heard it's totally fine to do this, and it's totally fine that algae is growing, as this is a synthetic coco grow with high perlite content. They also don't seem overwatered, they're all pointing against the light, seem happy, but the leaves just show problems as of 2 days ago.

I'm scared that things will go wrong from here onwards. I don't want them to die, I was so happy when they arrived. Can someone please tell me what's going on here? I can provide all details if needed.

Highly doubt it's the light as long as everything is in range they can handle lots of light early. Probably more then likely a environmental issue or nutrient balance

hake & add Canna Calmag Agent until 200ppm

I'd cut that in half I buffed my RO water with water soluble gypsum and epsom 50-100 only then add base nutrients looks like to much Ca and N

 

[Lil Dab]

Also 1.6EC is a bit high for that age that is my MAX ppm I hit for auto's generally see tip burn around 750 ppm and at that age I'd be much lower 500ppm+/- (hanna 500 scale)

 

[Kazooey59]

That's the weird thing - It's only two of them. No tip burns, just strange yellow coloration between the veins. I've never seen this in my life, and I went through MANY problems, let me tell you that. I was cursed back then.

Here are, for example, my two Granite Haze F5 from Speedrunseeds. One is around 14 days old, the smaller one is 8 or 9 days old. No symptoms, no problems I think. Getting 800PPM (200ppm calmag + 600ppm Canna A+B):

Here are both the Acid Snows from Speedrunseeds (also 8-9 days old since sprout), considered one of the most heavy feeders of their strains. Both show these weird yellow chlorosis everywhere, spreading across every leaf, first old leaves, later on the newer leaves:

They're all getting 1:1 the same formula, I wrote it down on a sheet to not make any mistakes. Are you sure that lowering Calmag would fix this? I have not seen one person who was able to identify this symptom, people could only guess out of pure assumptions

 

[Lil Dab]

They're all getting 1:1 the same formula, I wrote it down on a sheet to not make any mistakes. Are you sure that lowering Calmag would fix this? I have not seen one person who was able to identify this symptom, people could only guess out of pure assumptions

Well there's no gurrantee's that's for sure IMPE most the time it's from too much of something especially when feeding that much just my opinion but if you cut it in half and the problem goes away then there's your answer If it gets worse well there's your answer too

 

[Mañ'O'Green]

That's the weird thing - It's only two of them. No tip burns, just strange yellow coloration between the veins. I've never seen this in my life, and I went through MANY problems, let me tell you that. I was cursed back then.

Here are, for example, my two Granite Haze F5 from Speedrunseeds. One is around 14 days old, the smaller one is 8 or 9 days old. No symptoms, no problems I think. Getting 800PPM (200ppm calmag + 600ppm Canna A+B):

View attachment 1690028View attachment 1690029

Here are both the Acid Snows from Speedrunseeds (also 8-9 days old since sprout), considered one of the most heavy feeders of their strains. Both show these weird yellow chlorosis everywhere, spreading across every leaf, first old leaves, later on the never leaves:

View attachment 1690030View attachment 1690031

They're all getting 1:1 the same formula, I wrote it down on a sheet to not make any mistakes. Are you sure that lowering Calmag would fix this? I have not seen one person who was able to identify this symptom, people could only guess out of pure assumptions

I am not sure it is a symptom? the coloration crosses the veins which is unusual in a magnesium lock out. It may be a little bit of variegation which is genetic. The plant is young and they often show strange growth early. That said are you fertigating properly? Start no sooner than two hours prior to lights on and stop fertigating two hours prior to lights out. Fertigate to a minimum of 20% run off to waste every day you fertigate. If you are doing recirculating recirculate the volume of your reservoir each day and watch the PPM when it drops by 100 - 150 PPM change the reservoir. PH to 6.8 as often as you can. The ok range is 5.5 to 6.1