Burned leaf edges in coco

[Rookie4]

Hello, on my current grow i am selecting Ice Cream Cake x Red Velvet and London Pound Cake x Red Velvet from Lit Farms. Since like 4 weeks ago some leaf edges started turning yellow, and new branches had light green colour. Even after i added more nutrients, it didnt help. Also my garden is infected with fugnus gnats, that i cant get rid of, i am curently waiting on my shipment of bio control to try fight them off. Does anybody know if it can be done by gnats, or what could it be? Thanks.

Running under:
660w sunritek mh6 80% power at +- 60cm height
5,7 pots, getting runoff each watering
Canna Aqua 1,3EC 6,1PH
day temps 26 degrees celsius, night temps 20

 

[troutman]

Coco needs extra calcium and magnesium. It's why people like to use some cal/mag with it.
Until the biocontrols show up try to get sticky fly tape. I use some in my garden all the time.
These days, I set sticky tape in my grow tent in every corner before I set even one plant.

 

[Bush Dr]

You’re scorching them …. set the light @50% and do as troutman says ….some hydrotons on top will slow down evaporation too

Since you haven’t established beneficial bacteria in the coco you can use hydrogen peroxide to kill the gnats

 

[Rookie4]

Thanks guys, i am using canna calmag at dose 30ml to 50l to get 0.4 ec with water, as canna says, do you think i should add more? I am gonna try to dim the led but it also happens with my critical 3.0 that are under 400w hps. Appriciate your help

 

[exploziv]

Yes you should add more Ca and Mg.

 

[Creeperpark]

I always use yellow stickies to catch whiteflies, gnats, and other flying insects. Every indoor grow should use a lot of these yellow stickies every time. The gnat mistakes the yellow color for a dead yellow leaf and lands to make a home. When they get stuck to stickies, no more babies! If you don't use them you may have a hundred gnats laying eggs in a couple of weeks.

 

[Three Berries]

Mosquito bits in your nute water will cut down the natters.

 

[Rookie4]

Hello, i added more calmag, and also little bit more nutes (running 1,4-1,5EC) and i calibrated my PH meter. Its wierd to me because it’s like my 6th time in coco with canna and this never happened to me. I am running my led on 40% and this showed over night after new feeding. I am absolutly desperate with this, because i need to switch to flower. This exess/deficency is even stuniting new branch growth, this burn occurs only on upper new leafs. on some plants on bottom
It is wierd that some plants are are okay and others fu***d. I dont know what to do more about it

 

[Rookie4]

On gnats, i will try steinernema feltiae (predatory nematodes) and Bacillus thuringiensis root drench every 2 days, sticky traps and aphidius colemani (predatory mites) for additional control

 

[bigpeter]

Canna Aqua is not a coco nutrient. Maybe try some Canna coco A&B or something that is coco specific?

 

[Creeperpark]

In order for calcium to move from the roots to the leaves, the plant has to move water throughout the plant and transpire out the stomata. If you have less or no transpiring your plants can get calcium problems. Make sure the plants in question are moving a lot of water for calcium uptake. If the plants have stopped moving water then that's the problem.