Cal deficiency?

[NorthernLights_420]

Strain: Girl Scout Cookies Auto
Water: 0ppm RO water
Grow medium: Biobizz light mix soil
Nutes: Mega Crop 2 part
Ph: Always 6.4 to 6.6
PPM: 500 to 550 ppm (.500 scale)
Latest feedings: 2 grams part A Mega Crop. 1.5 grams part B Mega Crop.

I am only seeing these spots on the GSC in my tent. So I dont think its rust. I was thinking calcium deficiency but not sure so wanted to ask on here? Thanks

 

[NorthernLights_420]

@Mañ'O'Green Any clue bud?

 

[Mañ'O'Green]

How often are you feeding the soil? Are you watering to run off? I cannot tell if you are feeding too much or too little. One of the classic problems of using a precharged soil. I need whole plant pictures in regular daylight -turn grow lights off. It is a calcium problem but could be from too much magnesium in that precharged soil?

 

[NorthernLights_420]

(Feed water water) I water each plant when needed with a quarter to half gallon each morning if needed depending on how big they are and how fast there drinking.

 

[Arthur]

Don't use RO for plain water days.