Please help!

54 days from seed in 3gal fabric pots filled with coast of main and harvest hero I have been watering with RO water it comes out a PH of 7 and at the start I just did straight 7 but that darkening had me weirded out but I also started getting lime green almost yellow new growth so I thought maybe it was a CAL MAG issue so I tried a SUPER small amount and it seemed to “work” but then I started to get clawing on my plants and it could be from the nitrogen base in the cal mag itself but I’m not 100% I cannot find a single picture of any leaf deficiency that looks exactly like this one I’m at my Witt’s end and just do not know what direction to go please help

Calmag has nitrogen

You need to stop using it
EDIT:

WELCOME TO RIU

Your soil only requires water at this stage. Plants too small to need cal mag. Just run straight water. If something happens come back.

Here is my 2 shekels on this ….

You have typical inter vein symptoms associated with magnesium deficiency ….. a mobile nutrient that can be easily corrected .
Your RO water is filtered and can strip certain good minerals along with bad stuff. Coast of Maine is as with other peat mixes supplemented
with buffers - so you can run TAP water. Municipal city water will be fine for use in most grows.

As far as correcting , forget CALMAG use Mag Sulfate ( Epsom ) either in Foliar Spray or spooned on top soil and watered in.
Foliar application is the fastest absorption method … 2 tablespoons per gallon / add mix to spray bottle and use.
Or Top Dress about a tablespoon then watered in.

You are probably falling just out of range of ph uptake for that element.

Also … if you want strong ass plants .

Use silica . I use the same way … in a spray bottle.
Armor SI or similar.

I would like to thank everyone who chimed in to try and help, my girls look healthy as ever a nice lush emerald green did 2 low dose foliar sprays with mag sulfate and a lite top dress the results and turn around have been amazing now I can confidently do my flower transition and sleep easier knowing they are not as stressed!

Budzbuddha said:

Here is my 2 shekels on this ….

You have typical inter vein symptoms associated with magnesium deficiency ….. a mobile nutrient that can be easily corrected .
Your RO water is filtered and can strip certain good minerals along with bad stuff. Coast of Maine is as with other peat mixes supplemented
with buffers - so you can run TAP water. Municipal city water will be fine for use in most grows.

As far as correcting , forget CALMAG use Mag Sulfate ( Epsom ) either in Foliar Spray or spooned on top soil and watered in.
Foliar application is the fastest absorption method … 2 tablespoons per gallon / add mix to spray bottle and use.
Or Top Dress about a tablespoon then watered in.

You are probably falling just out of range of ph uptake for that element.

Click to expand...

How often should I use the epsom?

Budzbuddha said:

Also … if you want strong ass plants .

Use silica . I use the same way … in a spray bottle.
Armor SI or similar.

Click to expand...

And definitely apply silica in foliar spray. Far better absorption. Keeps feed EC lower. However to be effective it needs to be applied from seedling stage until flower.

I find the quick absorption of foliage applications superior than from root applications.
‘Separate from mixed feeds …

Budzbuddha said:

I find the quick absorption of foliage applications superior than from root applications.
‘Separate from mixed feeds …

Click to expand...

Magnesium and silica especially. However, less experienced growers, do not foliar spray cal mag. Magnesium sulfate only and it must be unscented. Very important.

Early Stage Magnesium Deficiency.

Add even less calmag than you did last time and measure it so you know how much to add to your RO water for your growing situation.

If it's not measured it's not managed.

Different Genetics as well as environments will require different amounts of things like Magnesium in the plants. Calcium & magnesium go hand and hand is why it comes in a supplement and usually those supplements include Iron and other minerals so the water isn't stripping the rootzone of minerals. Remember water is a great solvent, it likes to absorb anything it comes in contact with including calcium & magnesium.

If you're growing in Coco Calcium & magnesium bond to the coco until its fully charged, literally then after that unless it breaks down you actually don't always need to keep using the calmag supplement.

Just a tip for yah !

If you want to lower and raise ph.. use vinegar or baking soda ..in your case you would want vinegar to go down from 7.0 to maybe a little more of 6.5-6.8range

it dosent take a lot to get you up or down just mess around and you’ll see what it takes to get where you wanna be

I use CYCO Platinum nutrient line with RO water and haven't had to use a PH pen in years in coco.. 1.8 EC VEG 2.0 EC Flower

Always ends up in that sweet spot of 5.7-5.9

hotrodharley said:

And definitely apply silica in foliar spray. Far better absorption. Keeps feed EC lower. However to be effective it needs to be applied from seedling stage until flower.

Click to expand...

I'm a newb. My ArmorSi goes right in my feed.

Can anyone chime in on why the leaves turn a dark shade of green almost from the outside of the leaf??? They are drooping a bit and looking sad could I have added to much magnesium?