I need help with these plants with 2 things. When ...

I see you haven't yet resolved this question Telttailija perhaps its because you were looking for more information about topping? The primary thing to understand about topping a plant is whats known as apical dominance. The Apical node(highest) produces an Auxin(hormones) that inhibits the ability for 'lateral dormant' nodes(lower ones) to collect nutrients allowing the top most apical site to receive more nutrients and hormones for itself! (GREEDY!!) When you top a plant you are removing the Apically dominant node and creating new ones in its place from the two closes later dormant nodes. This is very handy in allowing to to spread out the growth of your plant across a space as apposed to up in the air! Fancy huh? Hope I helped you resolved this question and gave you insight into WHY you top so that you can better determine when to top (I personally top on the 4th node.) Feel free to ask any more questions! 😎

Hello @Telttailija !First of all if the RH is truly 10% you seriously need to fix it. At 28 °C the humidity should be at 75% - 80%. What you have there is a nitrogen deficiency and it's not coming from a PH problem. It's not from a PH problem because nitrogen is simply available at all PH range from 5 - 7.5 when growing in hydroponic mediums and for the first days of their life they were at rock wool which is a hydroponic medium. Also if the roots had touched the soil and the PH was out of range they should be having more deficiencies plus you can't mess up the soil PH by watering a couple of times with 6 PH. The problem is that you used a rock wool for the germination. Rock wool has no nutrients and you have to water with an EC around 0.8 ms/cm ( you need to buy an EC/PPM meter ) and in the hydroponic PH range from day 2. Also rock wool needs very often watering ( especially if you have 10 % RH and 28 °C ) so you might have also under watered at some point. Any way grab an EC/PPM meter and start feeding with 0.8 ms/cm until the roots touch the soil or just wait till they touch the soil anyway and the plants will start growing better and greener. Off course don't top them until they come back. Happy growing ! 👊

hello good question, in my opinion this is environmental. your humidity is very low. plants in this stage require higher humidity if possible. like in the 50-60% range. maybe this is affecting the growth rate as well as pH level in soil? either way soil pH is a bit low also and should hang around 6.7 for soil. to remedy possibly add root auxins (horomones to promote root growth and help plants that at in shock or stunted.) add a "passive humidifier" if nothing else to help remedy humidy being so low. to fic pH problem flush with clean, properly pH'd water (spring water if possible) lastly proper foliar feeds work wonders if getting a plant to bounce back to health.they should pick up growth soon hang in there!

From what I can see here is that your set up at the wrong PH levels for soil the ideal range for PH in soil mediums should be 6.5 - 6.8 I advise you raise the PH slowly so your plant(s) don't go into shock stunting their growth and blocking out nutrients . It's important to know your PH ranges for your mediums this way you can ensure no nutrient lock outs happen based on PH. I might also suggest raising the humidity in your room being at 10% it isn't very optimal for seedlings or plants in veg you want this number to be around 45-50% during the day and 55-60 at night . When plants are young they do some uptake through their leaves this is why its important to have high humidity . As for your nutrient solution I wouldn't use any nutrients for the time being until you get your plant nice and healthy again ! When you do decide to start using nutrients again I would recommend only starting with 1/4 strength and only feed them nutrient watering's every second or third watering . You also wanna make sure you don't over water your seedling water only when the soil is bone dry up to your first knuckle . This way you can ensure your plant goes through the wet and dry cycle allowing for your roots to expand more vigorously .As for topping your plant you can do it from the 4th node and up it's recommended that you wait till the 6th node this way you can ensure your tap root has grow to a good length because when you top your plant the tap root will stop growing and the little spider roots that have developed will become bigger . Over all your in good shape just a few minor things to fix up and you will be rocking and rolling ! I hope this information helps you ! - Happy Growing!

Ok starting what i see, i see small, yellowgreen seedlings,with very close together nodes. looking not so happy. Automaticplants have sensible roots, packing them into rockwool cubes may be the first mistake. Rockwool is tvery dense for the roots to break through, they like it easy with no barrier. If they meet an barrier, they may stop to grow, in worst case start to flower.I dont know what soilyou are uisng so i cant say anything to the feeding. but as if they are yellow in an big pot full of nutrients they having aproblem to get the nutes( wrong PH?). Automatic plants have a small window where the decision fall if they get big and healthy or not . that window is in the first 3 Weeks. I dont think they will be huge. And i wont top them the way the grow works, they are growing to slow for topping. Most plants respond very well to LST

If they are autoflowering strains, you top them above the 4th node, removing the 5th pair of leaves. If they are regular strains, you can TOP whenever you want, depending on how many tops you want to get (usually you wouild top them at the 5th to 7th node); but again don't do it too soon, at least no sooner than you would do an auto. In your info it says that you are using soil, but it looks like a soilless mix of perlite with something else or pure perlite? If it is soil, stop feeding and let the plants feed on the soil and don't water until the media is dry; if you are growing on soilless media (pure coco, pure perlite or something similar), then get an EC/PPM meter, you will need it to carefully meassure the feeds; at that size I would feed 0.5 EC (250 PPM)