Need help with autoflower deficiency

[budrow]

Hi, I have some autoflowers going in promix hp and about 2 weeks into flower the leaves started looking like this. It's mostly only the plants under this light. The other plants under the other light look much better for some reason but I don't see a light causing this. I have been giving bloom nutrients/ cal mag adding up to around 600ppm. My runoff was around 850. Possible lockout since runoff is higher than input? TIA.

 

[ArtfulCodger]

Burned tips, with the burn running down the edges...looks overfed to me. Runoff ppms higher than input supports that.

 

[Ninjadogma]

Burned tips, with the burn running down the edges...looks overfed to me. Runoff ppms higher than input supports that.

Looks like calcium and potassium damage. A higher runoff value can also indicate some pocketing is going on. Can be from an inadequate volume of water or watering too quickly and getting columning, ie water you pour in takes the express elevator straight to the bottom without wetting the dirt.

 

[budrow]

Looks like calcium and potassium damage. A higher runoff value can also indicate some pocketing is going on. Can be from an inadequate volume of water or watering too quickly and getting columning, ie water you pour in takes the express elevator straight to the bottom without wetting the dirt.

Should I just slowly water in some RO water with a tiny bit of cal mag? I have to add something to it so my meter will read it accurately.

 

[Ninjadogma]

Should I just slowly water in some RO water with a tiny bit of cal mag? I have to add something to it so my meter will read it accurately.

Looks like you're so close to the finish, no need to do anything drastic that will end up stressing the plant out, unless you're doing it for a stress response. But you can probably finish with plain water at this point... throw in some microbe food like molasses or seaweed extract if you use em, and that's it. There's also a little strategy in leaning into them at the end for some cool assists they lend to the finish. But keep an eye on that runoff too, you don't want the EC bottoming out on your plant unless you intend to. At the end of the day nobody smoking those leaves anyway.