watering while still moist to fix nutrient deficiency?

i've noticed my seedling has some slight yellowing along the bottom leaves. after ruling out nutrient burn i'm guessing that it's a nitrogen deficiency, as the other leaves have also taken a lettuce-like sheen to them.

i'm in coco right now and watered about 40 hours ago. thus far, my schedule is feeding every 72 hours after letting the cup go dry about 40%.

would it be better to wait the full 72 hours to feed again and let my plant tough it out to focus on root growth and avoid potential root rot? or would it be more advisable to move up the watering schedule (and increasing the ratio of Calnit) to give her the additional nitrogen needed? she's lost about 25% of water weight since the last feeding.

also, is something like nitrogen deficiency possible to bounce back from or will those leaves slowly die off?

thanks for reading.

how much is she drinking?

I water 200ml to about 20% runoff. Weight right after runoff is about 290 grams. Weight when I usually water is about 170 grams. Right now, after almost 2 days it's at 200g. So it's going at the same pace of about 40ml a day, I suppose.

I've read that watering just around the top portion could help with nutrient deficiencies but I feel like watering to runoff and clearing everything out with fresh nutes would be better.

My PH meter never worked, so after sending it for a refund a new one has yet to arrive. PH strips showing about 6 but who knows with the vague colours. I got some phosphoric acid yesterday and will probably PH down a couple drops but I'm not sure if I can track any difference on a litmus test.

I have no experience with coco. I know in regular soil, they say to let it dry first. Id still recommend letting it dry. If you just add a little and dont allow runoff, as you suggested, it will lead to salt build up. I know thats the case with soil. If you arent running 24/0, just do a light foliar feed. Thatd be your best bet if you dont want to wait for it dry up.

Userunknown said:

I have no experience with coco. I know in regular soil, they say to let it dry first. Id still recommend letting it dry. If you just add a little and dont allow runoff, as you suggested, it will lead to salt build up. I know thats the case with soil. If you arent running 24/0, just do a light foliar feed. Thatd be your best bet if you dont want to wait for it dry up.

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thanks for the tip. any idea what kind of PPM a calcium nitrate foliar feed would be ideal for a 3 week old seedling?

Thats something I have no clue about! Lol. I would either wait until someone else chimes in, or read to see how much it recommends for foliar feeding, and cut it down to 1/4 strength or more! Probably just give an extremely light dose just to help keep it from getting worse until she gets thirsty again.