Fast Buds Question about autoflower from first time grower

[tesctrees]

Thanks in advance to anyone who is reading this and takes the time to respond. A friend and I are working through our first grow with two 2fast4budz plants, an OG Kush and a Rhino Rider. We are on about day 25, and both plants seem to be healthy. They're in soil, 18/6 schedule with 150w hps light.

My question is regarding some yellow leaf tips that began to appear on some younger leaves of the OG Kushand a bit on the Rhino. At the time, about a week ago I wasn't able to pinpoint what they were symptoms of, and I gave them their first feeding of nitrogen nutrients (organic maxi crop fish liquid), about half a teaspoon per gallon(5ml). The Rhino plant has continued to thrive and grow speedily as the strain is said to in the veg stage, and has barely any signs of yellow leaf tips or any leaf symptoms. The OG Kush has continued to have yellow tips in the younger and new leaves, and we're worried isnt growing quite as fast. In the pictures you'll notice that the Rhino has more preflowering hairs on the budsites than the OG. Can anyone guess why the OG Kush would be experiencing these symptoms despite the two being in the same conditions? Is this something to do with the strains?
Last two pictures are Rhino Rider, first four focus on OG KushK

Thanks so much again for any advice.

 

[Cannaficionado]

Its too late in the game for heavy nitrogen feeding, thats a personal opinion and some may disagree, but it looks like sex is showing and the stretch started so I would taper away from veg feeds and switch to bloom/flower feeds. Your plant is super dark green. Meaning its already got plenty of nitrogen. My guess is maybe your ph is a bit funky or there is excessive amounts of nitrogen in your soil locking out potassium.

Along with this, you may wanna run some plain water ph'd to 6.0-6.3 for your next couple waterings or do a very light dose of flowering feed. What you're seeing is the effects of a non mobile nutrient deficiency, but that deficiency can come from an inadequate amount in the soil or it can come from ph lock out or can be locked out by improper proportions of other nutrients. Most likely those tips will not come back, watch future top growth. If you see yellowing starting at the bottom you can up the nitrogen heavy feeds by a little.

I only say cut back on the heavy nitrogen feeding because it takes a while for nitrogen toxicity to build up to levels where its dramatically effects the plants and in the span of a few weeks your nutrient balance can get really messed up if you continue to add nitrogen to the soil


I know this chart is complicated but its a pictoral diagram of the basic nutrient interactions that 99% of plants use. Solid line shows a negative interaction, so if you start at nitrogen, if theres way too much it stops uptake of potassium, while that sits immobile in the soil it will build up amd lock out calcium, once calcium starts getting locked out it snowballs fast, but you wont see visible signs other than an extremely dark plant for a while. My last grow had this exact thing happen. My biggest plant took the brunt completely nute burned everywhere, calcium deficiency spots on every square inch of the plant...by harvest time my sugar leaves had almost completely wilted and curled up into the buds. Not a great trimming experience, also some of the worst smoke ever. But that might have been my dry and cure, in fact im pretty positive it smoke quality wise it was.

 

[Bob's Auto's]

First off, to AFN brother!! Enjoy your stay here
Here's a deficiency chart I use

 

[DCLXVI]

Did someone call a necromancer? Resurrecting a thread from 2016.....

 

[Dab]

Did someone call a necromancer? Resurrecting a thread from 2016.....

I should have read the thread backwards

 

[Bob's Auto's]

OK, time to go to bed, Bob...