Hi guys, First time grower. Working with ‘Critical Purple’. I put my 2 germinated seeds in soil April 4 so they’re nearly 8 weeks old. They were started indoors in an ambient room setting but have been going outside during the day as temps are reaching 80 here. They are 14 and 18 inches with buds just starting last week. They are carefully watered with BioThrive mix nightly and seem to be very healthy until this morning - see pic with rust spots. Note: it is only happening to one plant and they are next to each other. I am guessing a Calcium / mag deficiency but it is occurring on the lower leaves and my research says it stars on the top? Also the spots seem much more evenly spaced than the pics I have seen. I have Humboldts cal/mag/iron coming here tomorrow. Any advice? Really enjoying the hobby and want to develop good habits for healthy plants. Thanks for your time.
Welcome to the forum.
Is this limited to the lower leaves?
So far yes. From the bottom to half way up. The first two sets of leaves.
It’s normal for cannabis to shed its lower leaves as the plant matures.
How about a pic of the whole plant?
Okay. I see it about half way up too. Some additional information will help us help you. Can you please fill out a support ticket? Fill out what you can, as some of it may not be familiar to a new grower.
A support ticket will help us help you. Can you please fill out a support ticket? Please include what type of water you are using (RO, distilled, tap.)
COPY/PASTE the below list into your forum post.
Answer these simple questions the best you can.
If you do not know, or do not use something; Just say so; Or post
NA (non-applicable)
• What strain, Seed bank, or bag seed
• Method: Soil w/salt, Organic soil, Hydroponics, Aquaponics, KNF
Soil brand and type
• Vessels: Pots, Grow beds, Buckets, Troths
• PH of Water, Solution, runoff (if Applicable)
• PPM/TDS or EC of nutrient solution if applicable
• Indoor or Outdoor
• Light system
• Temps; Day, Night
• Humidity; Day, Night
• Ventilation system; Yes, No, Size
• AC, Humidifier, De-humidifier,
• Co2; Yes, No
If growing Hydro some additional questions:
-DWC? RDWC? Autopots? Ebb and Flow? Other?
-Distance of liquid below net pot (DWC)
-Temperature of reservoir
-TDS of nutrient solution
-Amount of air to solution
Always try to upload a clear picture of any issues you may have to allow the community to assist you. Pictures taken under natural or white lighting are by far the best.
Add anything else you feel would help us give you a most informed answer should be included. Feel free to elaborate, but short and to the point questions and facts will help us help you in a more efficient manner.
• Critical purple Auto
• Method: RAW- Nitrogen Plant Nutrient for seedlings, BioThrive Grow 4-3-3 for daily watering
Soil brand and type Miracle Grow Garden Soil with 20% Perlite mixed in
• Vessels: Pots
• PH of Water 6.7 - 7
• PPM/TDS or EC of nutrient solution if applicable
• Indoor or Outdoor - outdoor weather and temps permitting
• Light system - 80W Full Spectrum LED indoors - East Pennsylvania sun when available
• Temps; Day, Night
• Humidity; Day 72 - 85, Night - 68 - 74 indoors
• Ventilation system; No
• AC, Humidifier, De-humidifier, - no
• Co2; No
Is that water going in, or the runoff pH?
Some people get away with using MG products for cannabis. Many don’t. It can create problems because it has time release nutrients which submarine your pH and nuke your plant with nitrogen every time you water.
Your plants seem to be tolerating it fairly well, but keep in mind that it can cause problems.
@WaterRabbit To start I’d like to say welcome AND I LOVE YOUR STAGENAME!! I hope you pair it with an avatar that suits it properly up it rocks!!
MidwestGuy will get you straightened out, he knows grows lol!! It’s interesting that both plants have had the same environment conditions and supplements and the one just started rusting up. It’ll be interesting watching you work through this to a resolution, please keep us posted!! Good luck!!
Some cannabis phenotypes are less tolerant of difficult conditions.
@MidwestGuy I know you knew !! And we now know we both knew you knoweded!! Lol Just learning daily bro.
You are usually pretty on top of things. 
Thanks for all of the quick responses guys! They weren’t started in the most optimum of environments. I will definitely not cheap out on the soil next time. I plan to do more and more upgrades in environmental equipment as I go. I’ll tune in here regularly to enhance my education - this seems like the best place to do that. I will keep y’all posted on the outcome. Thanks again!
@MidwestGuy Thank you for that kindness! I like your Shepherd pic recently. Those are my jam as well. Meet Elvis & Bailey.
@WaterRabbit That Support Ticket gives all readers your grow specifics, every one of has an individual situation. The details matter in the analysis otherwise we’re just throwing darts in the dark over here ok.
@Fieldofdreams what does he have in his mouth?
@beachglass your a gentle spirit Queeny. You don’t want to know.
Think of it as a fluffy chew toy.
nevermind, I just noticed the tail. 