Help! Yellowing spreading new growth

[KKB]

Hi my plants keep yellowing, they seem to be both nutrient deficient and nutrient burn?! I flushed and the problem didn’t improve, so I have gave them nutrients (canna A and B) the following week, now yellowing worse, so I flushed again with phd water and a little cal mag but no improvement. It’s like they don’t like nutrients at all? 600W LED lights, I keep moving further away but no more room to move up to, 8in pots, don’t really want to repot again as pots will be too big for area. Any suggestions what to try next?

[az2000]

They look like they're kept too wet too long. How long do you wait between watering? What soil are you using? (I don't see any perlite. I use generous it generously, maybe even too much.).

It could be N deficiency. But, when the soil goes through complete wet/dry cycles, the ph will swing a full point or more. When kept too wet, that ph is held lower, limiting the availability of N.

FWIW: "Flushing" would make either condition worse. There's no burnt tips (no sign of nute burn).

[Canuck147]

Next - try letting them totally dry out before adding anything else.

[KKB]

I use Cana Coco Coir, I didn’t add any perlite as read that it’s “hard to over water”, but this maybe the problem. On average I probably have been watering every 4 days, but recently increased to a week when the top soil looks dry. I thought maybe it was water logged early on, as slow growth and soil didn’t seem to dry out/ took ages to drain any run-off, I repotted to bigger pots and that helped it dry out more, but will try leaving it longer between watering as maybe the bottom still isn’t drying out enough

[az2000]

I've never grown in coco. I like my soil to dry in 2-3 days (when the plant has grown into the container. When the container's not grown into, it can take twice as long to dry. That can be tricky to keep it uniformly moist, but not fall into the trap of giving little sips all the time, never letting it dry as much as it should.

I determine when to water by lifting the container. You can keep another container full of medium (never watered) and compare what they feel like when you lift them. Or, you can let your plant reach the "too dry" state, where the leaves start wilting. It can almost look like overwatering, but it's a different kind of drooping which looks more like wilting. Lift the container to know what "too dry" feels like. And then try to get to close to that. It doesn't hurt to do that once, so you know what it feels like. I wouldn't do it to a seedling or flowering plant. It's a stress. But, it's not bad in veg. The leaves will bounce back in 20 minutes after watering. It's a tradeoff. One stress versus continually watering too soon. It's really surprising how light the container can feel (while still not "too dry." It won't feel natural to you. The only way to experience that is to reach the "too dry" condition once.).