SOIL Yellow leaf tips and edges

[Uriahjacob]

I am new to growing and I have 6 plants started from seed all sprouted within 2 days of each other. They are all from a plant I grew last year outside. I have them in a closet under a Phlizon PL 1000 Full spectrum LED. I started them in Fox Farms happy frog. Once they sprouted I transplanted them into 1 gallon pots with half happy frog and half ocean forest when they were five days old. I transplanted into dry soil and water each one with 22 ounces of dechlorinated tapwater ph to 6.3. I’m pretty sure that was too much water because the pots did not dry out for about 10 days. By then they all had their 3rd or 4th set of true leaves. Two plants had yellow leaf tips and edges on newer growth. I watered them for the second time with fox farms big bloom (3tsp Per gallon) and fish sh!t (1tsp Per gallon) 12 ounces per plant. After five days the soil was dry again. Three of the six plants still have issues with yellow leaf tips and edges but one plant worse than the others. The other three plans seem to be doing pretty good. I watered the plants a third time five days later when the pots were dry with 12 ounces of pH tapwater at 6.3. I’m including a picture of all of my plants taken today on February 16. And a close-up picture of the sickliest one. I was hoping for some advice on how to help this little one out. I have kept my grow room at a pretty consistent temperature between 70and 74° The humidity has ranged from 45 to 65 RH but has been mostly consistent at 55. I have a small 4 inch intake fan bringing air in from underneath the crawlspace of my house that stays on constantly with a small HEPA filter. I have a 6 inch exhaust fan exhausting into my attic that I have used at different speeds in order to maintain temperature and humidity. About three days ago I put in a cool mist humidifier that stays on all the time and has been keeping the room around 55% humidity. I now have the exhaust fan connected to my light and timer to come on on low only when the lights are on. Any advice or tips would be much appreciated.

[MrPNW]

Are they all the same strain? That looks like what happened to mine early on in veg. The grower I got the clones from said it was light stress. Besides the yellowing some of the smallest leaves up top were twisting in a spiral. I raised my light and lowered the dimmer and they snapped back fast.
mine were indica dominant.

[CaptainWiese91]

Looks like some of them wants some magnesium and iron.

[Rwise]

The soil is staying wet to long, if these are plastic pots did you add drainage holes? (up the sides?)
How much run off do you get? And whats the PH of that?
What are you using to PH the tap water?
And as ask above, what stains? Not all want the same things, not even in the same strain, just like us each one is an individual.
Can you raise the temps a bit as well as the RH?
From here this looks like a root issue.

[SoOrbudgal]

Too me the soil was too hot to start seedlings. Now that your here it's gonna take time to adjust the soil back down to help. Those are photos so there's plenty of time to fix an they are not that bad. You'll need to up the size of pots right? They are free seeds you don't know if they are male or female takes time for sex to show maybe under 12/12 usually shows sex.

[dilvish]

if the pots are taking 10 days (even 5 days) to dry out then something is off. Check your temp gauges are accurate. if your pots have good drainage and you are keeping your temps around 75F then the pots should be dry to the first 2 inches deep in 3 or 4 days. Don't wait until the pot is completely dry of course. The colder the grow area of course the longer it takes for the water to evaporate. Note: some strains like it more arid (Alaskan Purple for example) so humidity should be around 40 to 45 at those temps.

Fox Farm when fresh has enough nutrients in it to keep the plants going for 3-4 weeks, so adding nutrients to it at this stage (very young plants) is not a good idea. You should also check to make sure your PH levels are accurate... soil likes 6.5 and the water should be at that level. Remember when you do start adding nutrients to add the nutes to the water, mix well and then test the PH of that nutrient water. some new growers make the mistake of testing the PH level before adding nutrients.

[Uriahjacob]

First off thanks for all the feedback. I’m not sure what the strain is. They are children of a bag seed plant I grew outdoors last year. I had a very small amount of runoff on the first watering and I didn’t check the pH. I have been filling 1 gallon jugs with tap water and letting them sit opened in my grow room for at least 3 days. The p

[Uriahjacob]

The ph is 7.2-7.8 and I use white vinegar to bring it down to around 6.3. I have been using a PH pen I bought off Amazon for $20. I was able to add a defuser and my rh was at 60% this morning and all the plants were “reaching for the sky”. I noticed growth on all of them especially the biggest ones when I got home. If there is a root problem what can I do to help? The plants that are having trouble have been weak from the beginning. I was hoping to keep them in the 1 gallon pots until I can see some substantial pre flowers and then transplant them into 3 gallon pots when I know they are females.

[dilvish]

Did you calibrate the PH pen? do it just to be sure. Again if the pots are taking 5-10 days to dry out a bit (not totally I hope) then it's being overwatered. At that temp and with that high humidity I'd say they are suffocating a bit. Dial back the RH to about 40% and make sure you test the soil before watering. it should be as dry as I mentioned above. Also, the strain/type of cannabis may not like the white vinegar, especially if it's not being properly diluted. Again that's a good reason alone to check to make sure the PH meter is accurately calibrated.

If you can afford to buy a ph meter then you should also invest in a proper PH Down/Up solution. Most growers swear by it.

[Uriahjacob]

I’ve been calibrating my ph pen every 2nd or 3rd time I use it. It was freshly calibrated just before the last watering (declorinated tap water only ph 6.3). My pen came with 3 solutions 9.18, 6.86, and 4.00 that I mixed with 250ml distilled water. 1 tsp vinager in 1gallon of my tap water drops ph by about .8. But after a few days the ph will go up a bit. I have 2 questions. 1. Will my other 3 plants that are looking good be affected badly by dropping the rh? 2. I haven’t had enough runoff to test but I’ve found information on line that says I can mix half soil and half distilled water and let sit for 5 minutes then stir and test with my pen would this be acurate?

[Rwise]

In veg the RH should be above 50%, in flower drop it.