6k 18site Nutrient Problem! Rust Spots on Leaves, Help!

[BoneDaddy]

18 site RDWC
6000w
Cultured Solution Nutrients
Currently 410PPM
PH Currently 6.1
Strains: GDP, Triple OG (is this even a strain?), Cherry Pie
Ambient Temperature: 69 F
Water Temperature: 70 F
Relative Humidity: 50%


New to the forum here guys so hey :cool:. I am seeing rust colored spots and some yellowing on my leaves!I am new to this RDWC and having come from growing in coco this is definitely a different world. we're about week 5 of vegging from clones. all of these strains are adapting to the system differently. The large bushy ones are the GDP, the thinner lankier ones are the Triple OG and Cherry Pie, The Cherry Pie exhibiting the worst signs of rust spots and yellowing. I was feeding them very lightly for the first 2-3 weeks due to lack of a TDS meter and lack of RO water. once we got that sorted out we started feeding them according to the Cultured solutions feed schedule. My problem is i can't tell whether this is a burn or a deficiency. we added Cal/Mg at 3 mL/gal 24 hours ago (too heavy?). any insight is much appreciated, thanks in advance!

 

[Seamaiden]

Oh, shit... looks like you've had a Ca- for a while now. That's what it is--Ca-. Classic, IMO. Occurs on upper leaves because it's an immobile element. I also see slight P- and advancing Mg-.

Some charts for you.

You don't need to pay so much attention to the mineral wheel, UNTIL you get a better understanding of what each mineral does for our plants. In the meantime, it's good to know what minerals antagonize and synergize each other.

These are for diagnostics. This flow chart is important because it really highlights why knowing where on a plant an issue is occurring is key to figuring out what the problem is.

This chart shows the leaves, but not where you're going to see the issue. It also has a mistake in that it has calcium lodged over in the mobile elements section--calcium is an immobile element. It is also absolutely VITAL to plant life processes.

 

[BrianDirt]

This is soil, hydro is lower.

Agree with Seamaiden, I not a hydro but is the PPM a little low, should it not be in the 800-1500. The Ph is also high I think for hydro, 5.6 or 5.8 I think is better and could be locking out the cal needed and showing def!

Here is a link to the hydro section on the farm!https://www.thcfarmer.com/community/forums/hydroponics.29/

 

[Funkstarfish]

agreed, cal deficiency, luckily pretty easy to take care of. Firstly, get that pH in order, somewhere around 5.6 to 5.8 going in for hydro i think. and in veg i feed between .6 and 1.0 EC or about 300 to 500 PPM.

I have a feeling poor source water before the RO filter had some play here as i had similar problems on well water before RO. 3mL per gal of calmag is about right.

Hope you get it under control soon.