Leaf discoloration

[Old Toker]

Anyone know what may be causing these leaves to display this color? Growing DTW in 100% coco and they are about 7 weeks in veg. Seems like it might be a calcium problem although my coco should be fully charged. Ph is a steady 6.0. If calcium, should I lower my Ph? I have both CalMag and Flowering Cal if I need to add calcium. Getting ready to flip once I cure/fix whatever this is. Thanks in advance for any advice or suggestions.

 

[Creeperpark]

Yes lower your intake water to 5.8 and it should go away with the calcium you are using. Coco coir needs a pH level ranging from 5.5 to 6.3 depending on what stage of growth you are in. Starting pH is 5.5 - 5.8 during veg growth, and 6.0 - 6.3 during bloom, The lower pH allows a decline in the other macronutrients, giving calcium and magnesium more exchange sights to link up to.

 

[HempKat]

Yeah like Creeperpark says growing in coco is not quite the same as hydro but it's closer to hydro then it is to soil, at least based on what I've heard other say, I've only ever grown in soil. If this is correct though then your calcium is completely locked out and several other nutrients are beginning to be locked out. I'll post two graphics here to help you out one is intended for Hydroponic but as stated above the same ranges apply to coco, this will help give you a better idea of how the various ph levels affect the main nutrients. I'll also add a sick plant chart that help you to diagnose what is causing health issues in your plant and what the common signs are. What I'm seeing in your pictures matches up pretty well with calcium and manganese deficieny which both those nutrients would be locked out at a 6.0 ph in coco

 

[Old Toker]

Thank you Creeperpark & HempKat! I have lowered my Ph to 5.8 and hopefully that will do the trick. Any opinions on Mendocino Flowering Cal Mag? No nitrogen. Think a little might help? I'm using my tap water and it's pretty soft (56 PPM). I'm thinking adding 100 PPM Flowering Cal Mag might help solve the issue (along with 5.8 Ph) especially going into the stretch. Any opinions?

 

[HempKat]

Thank you Creeperpark & HempKat! I have lowered my Ph to 5.8 and hopefully that will do the trick. Any opinions on Mendocino Flowering Cal Mag? No nitrogen. Think a little might help? I'm using my tap water and it's pretty soft (56 PPM). I'm thinking adding 100 PPM Flowering Cal Mag might help solve the issue (along with 5.8 Ph) especially going into the stretch. Any opinions?

It's hard to say for sure not knowing the full complete history but I would say hold off for now. if you've been giving the nutrients you describe the deficiency isn't necessarily because you haven't been giving enough but because the calcium and magnesium were locked out due to the ph. So I would say get the ph right first and see if things improve before adding anything else to the mix. If there is a build up of nutrients in there from them being locked out, then adding more could lead to over fertilization and that could lead to a whole new set of problems.