Two possible deficiencies? Dark Devil

[Delty]

Strain: Dark Devil Auto from Sweet Seeds
Day: 59
Tent: 90cm x 50cm
Light: 2x MH TS600 running 18/6
Media:11 Litres of Canna Coco + perlite
Nutrients: Canna Coco line, loosely following 'light' feed schedule
EC: 1.1 (0.05EC rain water) & PH from 5.8-6.2
Climate: 24C day, 19C night

After showing some early defects (+tri leaf) she has rebounded and shown consistent growth, she mostly finished her stretch about a week ago and the buds have started forming nicely. I witnessed some slight browning on the tips of a couple of leaves during the stretch but didn't make any big changes. According to the Canna guide I introduced a little bit of PK (only half their rec) on their last couple of feeds, which upped the EC slightly - was this premature?

The brown tips of the claws of the leaves are now more common and in the last 2 days the leaves are starting to show fading around the edge and between veins. I have consulted the deficiency guide but would really appreciate an opinion on what changes I might need to make.

Thanks for any help you can give!

 

[Delty]

Pics of the symptoms attached

 

[Mañ'O'Green]

Your temperatures are running on the cool side. What are your RH numbers?

 

[Delty]

RH is 48%

 

[Delty]

Update: the yellowing seems to be more pronounced and spreading. Still on just 1.1EC of A and B (+rhiz etc), no additional Pk13/14.

I’m not experienced at identifying defs but appears it could be cal/mag and P? This coco (post week3 transplant) was partly reused so could be depleted?

Considering adding cal mag to next fert, not sure what else to do?

 

[Proph]

Update: the yellowing seems to be more pronounced and spreading. Still on just 1.1EC of A and B (+rhiz etc), no additional Pk13/14.

I’m not experienced at identifying defs but appears it could be cal/mag and P? This coco (post week3 transplant) was partly reused so could be depleted?

Considering adding cal mag to next fert, not sure what else to do?

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You may want to spend some time studying/learning how nutrients work and how deficiencies show/express.. It will come in handy for every grow. The symptoms on these leaves look nothing like a calcium issue. The yellowing on the outer leaf tips is a classic sign of a K issue.. I don't see any signs of over feeding/nute burn so this could be an actual k deficiency. Coco is inherent. It has no nutrients in it so reused coco is basically just plain coco.. What is your feed/watering schedule? Every day? Every few days? Do you always use nutes, or do you use plain water in between nutes?

 

[Delty]

Thank you for your input!

They are fed with every watering and watered minimum twice per day.

I’d been advised that although Canna coco comes pre buffered, reusing it can give cal mag issues.

I will add pk to the next fert and make sure the PH is within K uptake range

 

[Proph]

Thank you for your input!

They are fed with every watering and watered minimum twice per day.

I’d been advised that although Canna coco comes pre buffered, reusing it can give cal mag issues.

I will add pk to the next fert and make sure the PH is within K uptake range

You can also try raising the EC to 1.3 or 1.4.. Every plant is different, some are heavy feeders, some are light feeders.. Some sensitive some not.. So learn to listen to the plant more than people, lol.. Your plant is in flower so you won't see any improvement on the leaves.. Your goal now is to slow down or stop the spreading of the issue all together.