HELP! Diagnosing Leaves - Spots/Lighter in Color

[guilty]

I'm back again! 1 out of 4 of my plants has developed these spots and some of the leaves are lighter in color on 2 out of 4. I'll attach a picture of all plants. I went on the troubleshooter here, but I'm having a hard time distinguishing between light burn or nutrient (calcium or magnesium deficiency?) This is in coco under a 315 LEC. 5 gallon smart pots. General Hydroponics nutrients.

Here is my most recent feeding schedule:

Feb 24 - 3 gallons - week 5 schedule + 1/2 tsp/gal of cali magic + 1 tsp/gal hydrogard - 2.5ml PH down in 3 gallon - PH 6.3

Feb 26 - 3 gallons - week 6 + 1/2 tsp/gal of cali magic + 1 tsp/gal hydrogard - 8ml PH down in 3 gallons - PH 5.6

Feb 29 - 3 gallons - week 6 + 1/2 tsp/gal of cali magic + 1 tsp/gal hydrogard - 4 ml PH down - PH 6.3

Mar 4 - 3 gallons - week 7 + 1/2 tsp/gal of cali magic + 1 tsp/gal hydrogard - 6 ml PH down - PH 5.5

Mar 6 - 3 gallons - week 7 + 1/2 tsp/gal of cali magic + 1 tsp/gal hydrogard - 4 ml PH down - PH 6.1

Mar 9 - 3 gallons - week 7 + 1/2 tsp/gal of cali magic + 1 tsp/gal hydrogard - 4.5ml PH down - PH 6.1

Any pointers or help diagnosing would be greatly appreciated.

 

[Toker1]

2 things... for one GH makes a coco specific formula. Might want to check into that stuff instead of what you are currently using.
Secondly, are you following the recommendation the manufacturer suggests for the formula and set up you are using?
http://gh.growgh.com/docs/Feedcharts...TW_03216am.pdf

 

[guilty]

I didn’t realize there was a specific formula available for coco! I have been going off of this chart: https://www.growweedeasy.com/wp-content/uploads/2014/12/coco-coir-flora-series-schedule.pdf

 

[Toker1]

So those conversions to US from metric are a bit on the light side. For example week 4 floral grow calls for 4 ml (.8 tsp)... but on your sheet it only calls for 1/2 tsp.
The plants are hungry. Possibly deficient because of this issue.
And yes... here is a link to the coco formulas from GH.
https://generalhydroponics.com/cocotek-nutrient

 

[guilty]

Oh wow. Thanks so much! I thought Nebela had just converted the amounts but didn’t realize it was on the light side. I will up the feeding this week. I see the “Coco Tek” line from GH you mentioned as well. May give that a try next time around.

 

[Toker1]

Yeah... most of the time shooting for the lighter side is a safe bet. But some strains are more hungry than others are. Better to read the plant until you have grown her out a few times. Then you start to get a feel for how much nute she can handle.

 

[guilty]

Ok. So would you suggest I go full strength according to GH this week then back it off somewhere in between Nebula’s chart and GH and see how the plant reacts?

 

[Toker1]

Judging by the color... I would go in accordance with the GH chart link I sent from their website.

 

[guilty]

OK! Thanks again, I really appreciate it!