CalMag or phosphorus deficiency?

[sinned4g63]

I noticed a day or two ago that one of the older leaves on my plant was starting some brown spots. I have been figuring out balancing nutrients and pH but unfortunately this one snuck up on me. I looks like it's due to nutrient lockout (calcium in particular) from pH between either my reservoir or soil. Yesterday I tested the soil around 7 and the reservoir just above 4. The last time I refilled before this I added CalMag first to prevent the drop at the instruction of another member on a previous post but I guess something was still off.

Today coming home from work I noticed 2 other leaves I must have missed yesterday and the issue starting on a new leaf close to a flower node. I needed to top off over half the reservoir today and decided to remove as much as I could of what was left, which was a bit under 2 quarts, and refill with freshly treated water. I ended up preparing and adding 4000ml, the first 2000ml were untreated distilled water (pH 6.1ish and TDS at 6), the next 1000ml had 4ml of CalMag, and the final 1000ml were the other nutrients (base A and B). Reservoir pH dropped but seemingly not by much coming in at 5.2. Now my meter starts acting up holding around 5.4 after it's been removed from the water.. unsure why, I think it may be something in the water that stuck to the meter throwing it off, so I decided to use a chemical test kit. Came in red/orange indicating low so I added pH up bringing it to a solid yellow reading after doing 3 tests/doses of pH up in total. Guidance would be greatly appreciated!

Will the leaves recover if it isn't too late or will they need to be trimmed? I have been letting her do her thing, being an auto as my first grow I was afraid to stress it with any kind of defoliation especially during flower.

Edit for information:
The medium is coco choir buffered with CalMag. TDS and EC I will have to double check (I will be reporting back as soon as I get home with those numbers) as I am still learning a lot on EC specifically so the reading doesn't stick with me like pH and TDS. I believe my pH meter is having issues so I have been using a General Hydroponics test kit for better accuracy which I believe I've successfully adjusted to or close to 6, will be confirming that tonight as well. Distilled water only, consistently tests 6.1 for pH and 6 or for TDS before nutrients. I am using Vivosuns nutrient line which is Base A and Base B in addition to their Nutriboost and Bloomjuice. CalMag is from General Hydro. Per the recipe on my grow box recommends 3ml of each base per 1000ml, the others are less exact. I have been using 2ml of the Nutriboost and 1ml of the Bloomjuice (as of last week) per 1000ml, CalMag also gets 1ml per 1000ml per the bottle instructions.

 

[Creeperpark]

Hello friend. You are on the right track remember every setback is a golden opportunity to learn something. You need to give more details before anyone can help. Are you using a TDS meter or an EC meter? Do you have a good pH meter? What is the soil, fertilizer, and most importantly what type of water are you using?

 

[sinned4g63]

Hello friend. You are on the right track remember every setback is a golden opportunity to learn something. You need to give more details before anyone can help. Are you using a TDS meter or an EC meter? Do you have a good pH meter? What is the soil, fertilizer, and most importantly what type of water are you using?

I have edited my initial post with that information. To save some reading, it is buffered coco choir for the medium and Vivosuns nutrient line (base A and B, nutriboost, and bloomjuice) with the exception of CalMag from GH. I started the nutriboost about a month ago and the bloomjuice within the past week. CalMag was added to the dosing schedule maybe 2 weeks ago to be added first to buffer the reservoir but I'm starting to think I didn't use enough. If I remember correctly, after refilling and treating the reservoir, TDS was high at 2200 and EC was in the 700s (776 I think?). I'll be reconfirming all numbers tonight.

 

[exploziv]

If TDS was 2200, EC can't be in the 700s. And if TDS was really 2200, they are burned.. It does sound like you added a lot of milliliters per liter.

 

[sinned4g63]

If TDS was 2200, EC can't be in the 700s. And if TDS was really 2200, they are burned.. It does sound like you added a lot of milliliters per liter.

Yeah I probably didn't remember something correctly I usually take pics of the readings but I was so focused on the pH I forgot. I tried to remove as much water as I could from the reservoir so when refilling I tried to replicate what it would have normally got during a 2000ml top off. I've been trying to space them out more so I can add the CalMag first. So for example, I would do 2ml calmag on the first 1000ml, then 2ml of each base (4ml total between both), 4ml of the nutriboost (0-0-1) and 2ml of the bloomjuice (0-6-4) on the second 1000ml.

This week would be the first week I bumped things up at the recommendation of my recipe going into week 2 of flower. So this week I would be starting 2ml calmag for the first 1000ml (staying the same so as not to burn), then 3ml each base (6ml total), 4ml nutriboost, and 2ml of the bloom juice (bottle says to up dosage at weeks 3 and 4) for the second 1000ml. I didn't change things too much, I try to stagger increases of any nutrients and it's done well for me so far.

Sorry if my math makes it seem like a lot, I am typically adding nutrients for a 2000ml fill split between 2 separate 1000ml measurements. So I suppose that's why this week seems like a lot because it was a total of 4000ml with the slight increase in nutrients. A complete dry fill would be about 6000ml so I have to assume there was around 2000ml left of what's already been in the reservoir. I imagine that would have diluted the 4000ml refill as well.

 

[sinned4g63]

@Creeperpark @exploziv

TDS 826
EC 1792
pH spot on 6.00 after soaking in distilled water for over 5 minutes.

I have not touched the water since last night. These are my readings from my meters, chemical seems to concur at a yellow/slightly orange color possibly being between 5.5 and 6.0.

 

[exploziv]

To me it looks like P an Mg deficiency, so maybe you kept the PH too low in the past? Keep it around 5.8 - 6 and it should be better.

 

[TanzanianMagic]

I noticed a day or two ago that one of the older leaves on my plant was starting some brown spots. I have been figuring out balancing nutrients and pH but unfortunately this one snuck up on me. I looks like it's due to nutrient lockout (calcium in particular) from pH between either my reservoir or soil. Yesterday I tested the soil around 7 and the reservoir just above 4. The last time I refilled before this I added CalMag first to prevent the drop at the instruction of another member on a previous post but I guess something was still off.

Today coming home from work I noticed 2 other leaves I must have missed yesterday and the issue starting on a new leaf close to a flower node. I needed to top off over half the reservoir today and decided to remove as much as I could of what was left, which was a bit under 2 quarts, and refill with freshly treated water. I ended up preparing and adding 4000ml, the first 2000ml were untreated distilled water (pH 6.1ish and TDS at 6), the next 1000ml had 4ml of CalMag, and the final 1000ml were the other nutrients (base A and B). Reservoir pH dropped but seemingly not by much coming in at 5.2. Now my meter starts acting up holding around 5.4 after it's been removed from the water.. unsure why, I think it may be something in the water that stuck to the meter throwing it off, so I decided to use a chemical test kit. Came in red/orange indicating low so I added pH up bringing it to a solid yellow reading after doing 3 tests/doses of pH up in total. Guidance would be greatly appreciated!

Will the leaves recover if it isn't too late or will they need to be trimmed? I have been letting her do her thing, being an auto as my first grow I was afraid to stress it with any kind of defoliation especially during flower.

Edit for information:
The medium is coco choir buffered with CalMag. TDS and EC I will have to double check (I will be reporting back as soon as I get home with those numbers) as I am still learning a lot on EC specifically so the reading doesn't stick with me like pH and TDS. I believe my pH meter is having issues so I have been using a General Hydroponics test kit for better accuracy which I believe I've successfully adjusted to or close to 6, will be confirming that tonight as well. Distilled water only, consistently tests 6.1 for pH and 6 or for TDS before nutrients. I am using Vivosuns nutrient line which is Base A and Base B in addition to their Nutriboost and Bloomjuice. CalMag is from General Hydro. Per the recipe on my grow box recommends 3ml of each base per 1000ml, the others are less exact. I have been using 2ml of the Nutriboost and 1ml of the Bloomjuice (as of last week) per 1000ml, CalMag also gets 1ml per 1000ml per the bottle instructions.

Here's what's going on.

1. Always used bagged coco coir from cannabis specific brands: Canna, Plagron, Biobizz.

Bricks ofthen have to be buffered with brand specific buffers, and not just with calmag.

2. The pH is way too low.

The pH should be kept at a steady 6.0 throughout the grow. Coco isn't hydro, which requires a lower pH than that - and even for hydro, 5.1 is too low.

A low pH locks out mobile nutrients: N, P, K, and Mg.

3. The problem presents itself as a P or Phosphorus lockout.

Calcium has a more shotgun pattern of damage to the leaf, while Phosphorus deficiency looks more blotchy and infected. Also at least one of the leaves will curl upwards. Also, being a mobile nutrient, the damage starts in the lower or middle branches, and then works it's way up to the next node, and then the next. Calcium, being non-mobile, starts in the grow tips or the leaves closest to the light, while sometimes a lower leaf that sticks out and is exposed to the light also shows damage.

4. Distilled water

Distilled water needs to be remineralized. I've had luck with taking a 1/4 teaspoon of lavameal (micronutrients) and maerl (calcium, magnesium and micronutrients), putting that in a quart of R/O water for a day, syphoning off the clear liquid, and mixing that with another 3 quarts of R/O water to get a gallon of remineralized water. This I can say worked for me. However just tap water is less of a hassle.

I noticed that the chloride itself is very alkaline, and if you let it evaporate, both the pH and the EC drop pretty noticeably.

Conclusion

This is a buffering and pH issue.

Growing in coco should be very easy:

Use bagged coco coir from a cannabis specific brand that doesn't need buffering. Keep the pH at 6.0 throughout the grow. Use tap water, let it sit in the plant's room for a day or so, so it has the same temperature and chloride can evaporate.

 

[sinned4g63]

To me it looks like P an Mg deficiency, so maybe you kept the PH too low in the past? Keep it around 5.8 - 6 and it should be better.

I think so, the chemistry with these nutrients and mixing them seems a lot more in depth then what I'm used to in conjunction with different types of water. I didn't think the pH would drop 2 just by adding nutrients so I learned something there.

 

[sinned4g63]

Here's what's going on.

1. Always used bagged coco coir from cannabis specific brands: Canna, Plagron, Biobizz.

Bricks ofthen have to be buffered with brand specific buffers, and not just with calmag.

2. The pH is way too low.

The pH should be kept at a steady 6.0 throughout the grow. Coco isn't hydro, which requires a lower pH than that - and even for hydro, 5.1 is too low.

A low pH locks out mobile nutrients: N, P, K, and Mg.

3. The problem presents itself as a P or Phosphorus lockout.

Calcium has a more shotgun pattern of damage to the leaf, while Phosphorus deficiency looks more blotchy and infected. Also at least one of the leaves will curl upwards. Also, being a mobile nutrient, the damage starts in the lower or middle branches, and then works it's way up to the next node, and then the next. Calcium, being non-mobile, starts in the grow tips or the leaves closest to the light, while sometimes a lower leaf that sticks out and is exposed to the light also shows damage.

4. Distilled water

Distilled water needs to be remineralized. I've had luck with taking a 1/4 teaspoon of lavameal (micronutrients) and maerl (calcium, magnesium and micronutrients), putting that in a quart of R/O water for a day, syphoning off the clear liquid, and mixing that with another 3 quarts of R/O water to get a gallon of remineralized water. This I can say worked for me. However just tap water is less of a hassle.

I noticed that the chloride itself is very alkaline, and if you let it evaporate, both the pH and the EC drop pretty noticeably.

Conclusion

This is a buffering and pH issue.

Growing in coco should be very easy:

Use bagged coco coir from a cannabis specific brand that doesn't need buffering. Keep the pH at 6.0 throughout the grow. Use tap water, let it sit in the plant's room for a day or so, so it has the same temperature and chloride can evaporate.

Thank you for the detailed response. So, at this point you're suggesting that I should switch back to tap water and let it gas off before using to measure out nutrients. No problem. Do you have any suggestions on adjusting nutrients? And should I do anything about the affected leaves/branches?

Someone did mention using something specific for cannabis but the nearest store was about an hour away which is why I opted for attempting to buffer a brick. I admittedly only saw about using calmag to buffer it so those will be changes I will make the next go around. The pH should be addressed now. I'm topping off again tonight and will be checking the pH after doing so from hereout.

 

[TanzanianMagic]

Do you have any suggestions on adjusting nutrients? And should I do anything about the affected leaves/branches?

- Nutrients should be a total (water plus nutrients) of 1.0 EC or 500PPM through vegging. Add 0.1 EC of epsom salt for magnesium.

The way I grow in coco is:

Water EC: 0.45
Canna Coco A + B EC: 0.55
Epsom Salt EC: 0.1
Total EC: 1.1

Lower nutrient concentration and drying medium encourages root growth. Root growth is especially stimulated by phosphorus. The magnesium in the epsom salt keeps the leaves phototropic. Mg also helps nitrogen absorbtion.

- You should water only when the coco is dry before the lights go on in the morning.

This encourages root growth. Ultimately it are the roots that feed the plant, and teh bigger and healthier they are, the less nutrient solution the plants need.

- Leave the damaged branches and leaves on, until they're overgrown by new growth.

Unless they're crawling with insects, leave them on. The plant is using them as a store for mobile nutrients. If they're removed before the nutrient deficiency is resolved, the damage simply moves on to the next leaf, and then the next. Ultimately, that inteferes with the plant's photosynthesis.

 

[sinned4g63]

- Nutrients should be a total (water plus nutrients) of 1.0 EC or 500PPM through vegging. Add 0.1 EC of epsom salt for magnesium.

The way I grow in coco is:

Water EC: 0.45
Canna Coco A + B EC: 0.55
Epsom Salt EC: 0.1
Total EC: 1.1

Lower nutrient concentration and drying medium encourages root growth. Root growth is especially stimulated by phosphorus. The magnesium in the epsom salt keeps the leaves phototropic. Mg also helps nitrogen absorbtion.

- You should water only when the coco is dry before the lights go on in the morning.

This encourages root growth. Ultimately it are the roots that feed the plant, and teh bigger and healthier they are, the less nutrient solution the plants need.

- Leave the damaged branches and leaves on, until they're overgrown by new growth.

Unless they're crawling with insects, leave them on. The plant is using them as a store for mobile nutrients. If they're removed before the nutrient deficiency is resolved, the damage simply moves on to the next leaf, and then the next. Ultimately, that inteferes with the plant's photosynthesis.

Thank you for yet another detailed response. I try my best to research so I don't come from a place of complete ignorance, but I am a total newbie weeding though years of different responses online.

Is there a conversion for EC? My meter reads in 1000s, or what is labeled as us/cm. Are you starting with the water EC and adding to it in those increments to get the total of 0.45? My Base A and B are running low so I wouldn't mind trying some better/different nutrients if there's something out there "better formulated". I went through 2 or 3 different nutrient regimes on my fish tanks before I found one I liked.

For the affected leaves and branches, I'd be inclined not to trim them as I was rather apprehensive to do any of that to begin with being it's an auto. But I also know leaving dead or dying branches can inhibit the plant from putting nutrients into furthering growth of what's healthy. There's a good handful of leaves looking rather unfortunate.. maybe 6-8. They're all older leaves and on the bigger side so they may not be overgrown for some time if at all. Is it overly detrimental to leave them be completely?

 

[exploziv]

Nope, you are probably used to feeding way too much. 1.0 mS EC = 1000µS, but since µS is called microSiemens, many call that mS as well. So you gotta figure it by the scale if it. If it's in the hundreds or thousands it's µS, if it's 0.something or under 5 it's most probably mS as in milliSiemens.

 

[TanzanianMagic]

starting with the water EC and adding to it in those increments to get the total of 0.45? My Base A and B are running low so I wouldn't mind trying some better/different nutrients if there's something out there "better fo

Basically my water is about 0.45 EC. I add 0.55 EC of Canna A + B, and then 0.1 EC of epsom salt.

I pH it down to 6.0.

Thank you for yet another detailed response. I try my best to research so I don't come from a place of complete ignorance, but I am a total newbie weeding though years of different responses online.

Is there a conversion for EC? My meter reads in 1000s, or what is labeled as us/cm.

Unlike EC, PPM is not standardized, however most meters are on the 500 or 700 scale.

So 0.1 EC = 500 X 0.1 EC = 50 PPM.
1.0 EC = 500 x 1.0 EC = 500 PPM.

Are you starting with the water EC and adding to it in those increments to get the total of 0.45? My Base A and B are running low so I wouldn't mind trying some better/different nutrients if there's something out there "better formulated". I went through 2 or 3 different nutrient regimes on my fish tanks before I found one I liked.

If you're starting out, it is best to just start with a single line:

Canna Coco
Canna Coco A + B
Epsom Salt
Ph Down

There is more, however those are the basics.

For the affected leaves and branches, I'd be inclined not to trim them as I was rather apprehensive to do any of that to begin with being it's an auto. But I also know leaving dead or dying branches can inhibit the plant from putting nutrients into furthering growth of what's healthy.

Basically, with a mobile nutrient deficiency, the plant is reallocating N, P, K or Mg from the old leaves to the new growth. So the path forward is to first solve the deficiency, or you're just losing more leaves.

There's a good handful of leaves looking rather unfortunate.. maybe 6-8. They're all older leaves and on the bigger side so they may not be overgrown for some time if at all. Is it overly detrimental to leave them be completely?

Just leave them until they fall off. They're still supplying nutrients to the plant.