Mottled chlorosis, twisted fan leaves.

[buckfastley]

Hi this is my second grow. I'm running canna cocos full line with canna brand coco coir watering twice a day sometimes only once. I also use recharge and mamoth p occasionally. The leaves are yellowing between the veins mostly on the second set of true leaves and recently on the tips of the third set of true leaves. They also seem to be twisting sideways a quit a bit. Growth seems to be relatively unhindered, def more vigourus then my first grow. Any thoughts are appreciated, but considering I'm running the full line I'm not sure what to do...

Day 23
R.O. water
EC 1.1
Rh ~ 60 but was 70 for a couple days
Day temp ~74 Night ~66
PH 5.8 - 6
Ppfd ~300

 

[MIAutomatic]

Are you adding calmag to your RO?
Canna coco nutrients recommend starting with a base calmag EC of .4. The A & B contain calmag but assume you are starting with water at base EC of .4, check their grow guide/nutrient calculator it mentions this quite specifically.

I am feeling like the coco police today. Coco needs more calmag than soil or other hydroponic mediums. Without it the coco stores more nutrient salts preventing the plant from being able to use them and can eventually lead to lockout and nutrient toxicity. You appear to have early stage lockout on your hands.

Keep your other levels the same, add .4 EC calmag and watch it for a few days to see how she responds.

good luck!

 

[buckfastley]

Are you adding calmag to your RO?
Canna coco nutrients recommend starting with a base calmag EC of .4. The A & B contain calmag but assume you are starting with water at base EC of .4, check their grow guide/nutrient calculator it mentions this quite specifically.

I am feeling like the coco police today. Coco needs more calmag than soil or other hydroponic mediums. Without it the coco stores more nutrient salts preventing the plant from being able to use them and can eventually lead to lockout and nutrient toxicity. You appear to have early stage lockout on your hands.

Keep your other levels the same, add .4 EC calmag and watch it for a few days to see how she responds.

good luck!

I very recently got the cal mag agent from canna(watered with it for maybe 7 days), I also started foliar feeding cal mag the past 3 days. Should I flush the coco with r.o. + cal mag at .4 ec to get rid of the salts?

 

[MIAutomatic]

I wouldn’t do a true flush unless you really need it, but doing a heavy water with a bit of extra runoff, maybe 30-40% then check the runoff EC, will give you a good idea where you are at.

For a vegging plant like yours 1-1.5 EC is a safe range, although the upper ranges of that can still stress some plants, so maybe go on the low end till you get it sorted out.

I don’t think you mentioned if or how much you are fertigating, but you should always water till 10-20% runoff, this is especially important to do with coco.

good luck!

 

[Mañ'O'Green]

Are you adding calmag to your RO?
Canna coco nutrients recommend starting with a base calmag EC of .4. The A & B contain calmag but assume you are starting with water at base EC of .4, check their grow guide/nutrient calculator it mentions this quite specifically.

I am feeling like the coco police today. Coco needs more calmag than soil or other hydroponic mediums. Without it the coco stores more nutrient salts preventing the plant from being able to use them and can eventually lead to lockout and nutrient toxicity. You appear to have early stage lockout on your hands.

Keep your other levels the same, add .4 EC calmag and watch it for a few days to see how she responds.

good luck!

Actually the Canna Coco assumes RO water and I cannot find anywhere where it says to start with an EC of calmag at .4?

It looks to me like he is not fertigating to 20% run-off by the end of every fertigation cycle?

The magnesium problem the leaves are showing can be a lock-out caused by a salt build up of Ca or K.

 

[elcoloan]

I very recently got the cal mag agent from canna(watered with it for maybe 7 days), I also started foliar feeding cal mag the past 3 days. Should I flush the coco with r.o. + cal mag at .4 ec to get rid of the salts?

The magnesium problem the leaves are showing can be a lock-out caused by a salt build up of Ca or K.

@buckfastley did the symptoms begin after using the calmag? As MOG points out, you might have had a lockout due to the the 7 days of calmag watering + foliar calmag. If it began before, I'd venture to say it was a pH problem... try to aim closer to 6.0... even 6.1 or 6.2 will help with Mg def symptoms.

 

[MIAutomatic]

Actually the Canna Coco assumes RO water and I cannot find anywhere where it says to start with an EC of calmag at .4?

The information provided by Canna can be a little inconsistent, and that is frustrating. If you go to the actual grow guide/nutrient calculator it assumes a base EC. It won’t even let you use the calculator unless you put in a base EC amount, the default is .4 but you can enter any value that is not zero if you select the custom water hardness

Grow guide | CANNA Gardening USA

www.cannagardening.com

The first bullet point in the info you posted says to use tap water. The later mention of 0.0 EC further down is just giving you nutrient EC values assuming a base EC of 0.0, but no where does it say that you should start with water with an EC of 0.0.

Anyway, I don’t wish to start an argument about it but it reads pretty clear to me. They even give you two PPM numbers in the grow guide, one that represents the total EC/PPM + tap water (or adjusted RO) and one that is the EC from nutrients minus the EC from the tap water value you select before running the calculator.

I wish Canna was a bit clearer with their information, but based on many canna coco cycles, and the information from their grow guide I believe my current understanding is correct.

 

[Mañ'O'Green]

The information provided by Canna can be a little inconsistent, and that is frustrating. If you go to the actual grow guide/nutrient calculator it assumes a base EC. It won’t even let you use the calculator unless you put in a base EC amount, the default is .4 but you can enter any value that is not zero if you select the custom water hardness

Grow guide | CANNA Gardening USA

www.cannagardening.com

The first bullet point in the info you posted says to use tap water. The later mention of 0.0 EC further down is just giving you nutrient EC values assuming a base EC of 0.0, but no where does it say that you should start with water with an EC of 0.0.

Anyway, I don’t wish to start an argument about it but it reads pretty clear to me. They even give you two PPM numbers in the grow guide, one that represents the total EC/PPM + tap water (or adjusted RO) and one that is the EC from nutrients minus the EC from the tap water value you select before running the calculator.

I wish Canna was a bit clearer with their information, but based on many canna coco cycles, and the information from their grow guide I believe my current understanding is correct.

because their calculator defaults to .4 is not the same as them stating somewhere that you should start with .4 of Cal-Mag.

It may be irrelevant because the formula does not change between starting with 0.01 or .4 EC. The only difference is in the total PPM of the nutrients plus the starting water.

 

[MIAutomatic]

This is getting off topic, but I am certain you are just reading it wrong. You are obviously a very experienced grower, probably more than myself. But I have grown many cycles using the Canna coco line.

This is the first line in their directions:

• A ready to use fertilizer solution is made by diluting A & B concentrates in equal amounts with tap water

Tap water is the most important part of that phrase. All tap water will have a base EC and the ranges Canna provides in the grow guide .2 .4 and .6 are going to cover the vast majority of people. When you use these pre-set values instead of the custom setting it does change the overall ppm numbers on the guide to reflect the harder or softer water. The guide is not very smart, and only works properly if you use one of the three presets.

The other line you quoted:

• Recommended EC for Coco A + B is 0.8 - 1.8 mS/cm (Part A plus Part B and assuming source water at 0.0 EC)

This is just telling you what the EC range should be of the nutrient inputs you are are adding to your water minus its base EC.

As you will see in the last two columns of the grow guide they give you two different ppm numbers. The second to last column with the + is the value of just your added nutrient inputs, the last column is the total ppm with the EC/ppm value of your water added in.

It does not matter if you use good tap water with the correct EC range or if you mix your own using RO or distilled water, but the Canna coco nutrient line is not designed to be used with straight RO water without some base hardness, either naturally or added.

Sorry for mansplaining

 

[elcoloan]

It may be irrelevant because the formula does not change between starting with 0.01 or .4 EC. The only difference is in the total PPM of the nutrients plus the starting water.

Hmm... have you noticed that the calculator automatically changes the Schedule Type depending on the Water Type you choose first? And if you don't change the Schedule type after choosing the Water type, the ppms/EC (not including the EC of the starting water) they recommend do actually change:

type of water -> automatic sched type chosen by the grow guide
Soft Water ->Heavy feed ( min ppm 550 - max ppm 1005)
Standard Water -> Normal feed ( min ppm 450 - max ppm 905)
Hard Water -> Light feeding (350 - 805)

So, I think the OP should first verify the EC of the RO water he/she uses and let the Schedule type of feeding setting in the growguide as it is set automatically depending on the water type.
So, @buckfastley, I'd recommend that you just continue watering as you have but without calmag or anything else (their own guide doesn't seem to include using any kind of calmag, not even Canna's own calmag product), and just using the grow guide calculator and choosing the water type according to its EC and don't change the schedule type. If this doesn't work, try using a pH between 6.0 and 6.3. If neither work, I'd contact Canna.

Please let us know how it turns out.