What deficiency or excess is this?

[diabolito]

I'm growing 4 plants of the same strain ( GMO x MAC seeds ) , in Promix and Perlite. I usually grow RDWC so not totally up to speed on Promix growing. The plants are being given veg nutrients at a PPM of about 400 when watering when just about dry.

I have yellow-brownish marks on the leaves on 2 of the 4 plants.

Can anyone identify the deficiency or excess? One thought was maybe it's dripping some of the nutrient water on the leaves, if that could cause this. I've looked at some charts but can't be sure.

Thanks

 

[Tokin Roll]

Probably calcium.

 

[Phytoplankton]

The first picture shows a plant with a LOT of N (very dark green), and while I agree with @Tokin Roll that's it's probably Ca, it also (first pic) looks like it could be a combo of nute burn and CA deficiency. Are the leaf tips on the first pic crispy? I'd start adding cal-mag and maybe tone down the N a little, at least on the first plant. Dripped nute solution can cause spotting too, try to avoid that. Keep a close eye on them and see if calmag helps. You won't fix the damaged leaves, but you shouldn't get more.

 

[SmokingWings]

The first picture shows a plant with a LOT of N (very dark green),

I noticed that but figured that the dark green color was caused by a bad exposure selection by the camera or phone; I am thinking that the flash did not go off.

Are the leaf tips on the first pic crispy?

Does look like it, doesn't it. Drying leaf tips is one sign of a possible Magnesium deficiency so.....

I'm growing 4 plants of the same strain ( GMO x MAC seeds ) , in Promix and Perlite. I usually grow RDWC so not totally up to speed on Promix growing. The plants are being given veg nutrients at a PPM of about 400 when watering when just about dry.

.... It is possible that you already have some Cal-Mag supplement that can be used for this ProMix grow.

 

[diabolito]

Thanks guys. I have taken the advice and added a Cal-Mag Supplement.

You're right the colour is off in the picture but they are quite dark green so I'm backing off on the other nutes a bit.

I'll give them a little time and see how they go.

Thanks for the help, really appreciated.

 

[SmokingWings]

You're right the colour is off in the picture but they are quite dark green so I'm backing off on the other nutes a bit.

The one you have to keep track of is Nitrogen. Backing off a bit on the other nutrients to solve a possible Nitrogen overdose could lead to other deficiencies. Something to keep in mind.

 

[cbdhemp808]

My first impression of that top picture is a water-related issue... the leaves look stressed. What is the pot size? Can we see a pic of the whole plant(s)?