Lsd-25 seedlings issue

[Totalnoob]

Problem: leaves yellowing

Medium/grow method: soil- happy frog in top half of pot, ocean forest Inot bottom half.

Feed: and supplements used: none currently

water source: well water. Ph adjusted down to 6.2-6.7

Strain/age: Fastbuds LSD-25 sprouted 4-24

light used: 23w 5000k cfls within 2 inches

Climate: lows to 70° highs to 90° humidity between 25-35%

Additional info: I have two that are yellowing, but I have a third that matches every other parameter above aside from being planted in in a pot with only ocean forest. That plant seems to be doing fine. No yellowing. That is the one in the terracotta colored pot.

 

[Waira]

-- could be a couple things,.... the high T and low RH% are hard on seedlings, so try to get those Temp's down and the RH% up....
Also, I suspect some lousy soil, likely badly off pH, a very common problem with soils,... they are a real craps-shoot! I personally have tested bags of both HF and OF in the low 5's pH- ... seedlings this young aren't suffering from defc.'s, and that yellowing is a sure sign they do not like that soil,... Oddly, you better one is in straight OF? Often as not, OF is a bit too hot for seedlings, HF is fine,....
So, testing the soil pH is critical at this point! Do you have a meter, or best of all, a quality soil pH probe? Using bag soil, with the meter, you can do a quick slurry test: 1cup soil, 1 cup usual water mixed well, let it sit for an hour, then test the slurry for pH; clean the electrodes and bulb well with RO/DI water,...
Or, a crude run-off test: 1l or qt. soil, moistened until just starting to run-off; let sit for an hour, then slowly pour water in until you get a few oz's of run-off collected in a clean container; test for pH,...

Worst case, the soil is shit, and you can try to flush it with 7.0 pH water, 2-3x pot volume of water, which may help raise the pH in there,...

 

[Totalnoob]

Could it be strain dependent as well? I have 22 other plants and none of them are exhibiting these symptoms. All potted from the same bag of OF and HP. I will do the runoff test tomorrow. Thank you for the help. Here's a shot of my other plants that popped the same time.

 

[Waira]

...sure, my bad, that's also a possibility! ...breeders, pheno' hunters, and the like will burn through scores of seedlings/young plants to select the best,.. regular growers though roll the dice seed to seed, and all certainly aren't gonna be winners! Different strains will have different tolerances and preferences too,.... do the slurry or r-o test still, yes,... Aslo, try to keep more even constant moisture on the seedlings, with the low RH% in here,.. a mister works great for surface moistening, but heft the pots too occasionally to check overall moisture,....

 

[Totalnoob]

Did the slurry test. 1 cup of OF, 1 cup of water (7.0Ph). Sat for 80min. Tested at 5.6Ph. I know that's low, but not sure by how much. Is 5.6 the actual ph of the soil or is there some math involved because of the 7.0ph of the water?
Is there a good low cost option for increasing humidity in my grow area?
I try not to overwater. I've got a scale and I weigh my pots every day or so. When they get down close to the weight of the pot I've never watered (No plant) I water them. Thanks again for the help.

 

[Totalnoob]

Here are a few current shots. I've been watering with water at 7.0 with half strength Biothrive from general organics. The plant in the fabric pot is a GSC from fastbuds that was in the same pot size as the lsd until yesterday. I put them side by side for comparison sake. Perhaps it's just the strain, but I'm at a loss. Thus is my first time growing anything, and the rest of my ladies seem to be doing well.
Also, I put everyone under a 600w MH 3 days ago and they have responded well.

 

[Waira]

pardon the delay mate!
... yup, as suspected, way off pH ,.... 5.6 is an estimation, but a reasonably accurate one I believe... As for the 7.0 water, that depends on how hard the water is, it's CaCO3 content, measured by TDS meter (ppm's) or an EC meter,... did you pH adjust this water, or is it "as is" from the tap? If so, then at 7.0, it's pretty soft water, which is good indeed! If it's hard water that you adjusted, then this is where the measurement skewing will be, likely making the reading less acidic that it really is,.. but the slurry test is better than run-off test and calculation!
I admit, I'm a little shocked the other plants are doing okay,... how old are they? I won't tell you to fix what ain't showing as broke, but yes, I'd stay with watering at 7.0, maybe higher... back to that water hardness deal again-- more minerals in there will offer stronger pH buffering. do you have a Ca-mg product? .... I strongly recommend a basic, inexpensive TDS meter so you can test your water and just see,...ditto for a pH probe, like the Accurate 8- hsoil:- (the long probe unit here)... avoid the cheapo skinny probes you see around at garden centers, etc., they suck! Big picture here is, having such tool will help you understand and adjust your water and nutes better, and more important,keep an eye on the in-pot pH,.. adjusting your water/nutes (if needed) will go a long way to maintaining proper pH in-pot! It's 10x the beating to fix off-pH in pot vs. making little tweaks here and there to help maintain it; there are several other influencing factors in-pot as well, from the roots themselves to the soil microbes,... do you use any inoculants, BTW?
.. watering,... I think when the pot is 50% lighter than when well watered, it's time,.. but weighing is a pain, so that's why I say to learn the heft test; just "calibrate" yourself with wet and dry-ish (not totally!) ones,... seedlings want more even consistent moisture levels,.. some surface drying is oK, but never to the point of then stressing/wilting....
... a wet hand towel hung in a open well spread way (more surface area exposed) can help in a tent, maybe squeak out another 5-10%RH,....
....looking at that LSD, it's very yellow on newest growth (not sure how much the light is behind this?),.. but such symptoms indicate a defc. in an immobile nute element, usually Fe or Zn,... odd at such a young age,... oder still, it's usually happens when the soil gets near 7.0 pH, which ain't the cae here, so it's likely a uptake quirk causing a lack-of type defc., not a pH lockout type,... I've had some plants like this, fought the defc. for weeks before finally getting ahead of it,... goes back to that sub-par seedling thing, a gamble with all seeds,....
shweeet!- on the HPS! Make sure it's plenty high up, seedling don't like the intensity of light that older plants do,.. and down-side, your struggles with RH% just got worse, unless yours is ducted and cooled very well,...

 

[Totalnoob]

Thanks for the invite depth reply. I actually have to phone down from 7.5ish out of the tap. Temps are more stable in the mid 70s and 40-50% humidity with the new lights. Everyone else is good, apart from being a bit behind. I think the high heat and the low humidity as seedlings slowed them considerably. I just topped 3 of the 9 GSC above the 3rd node, and the others just aren't ready. I'm not sure they will be ready before the 21 day Mark, and that what I read as the last day you should top an auto. Any advice to that point?
I've given all the girls one feeding of biothrive at half strength so far, and will be feeding again tonight, so perhaps that will help my lsd come out of it's funk. Thanks again for your help, I'm trying to do the right things, but having zero grow experience has left me lacking in many areas. Here's a shot of my ladies all together, and a GSC by itself that seems to be doing a bit better than the others. These are day 18 from breaking the soil.

 

[Totalnoob]

Just realized autocorrect got me a bunch of times. :/
Anyway, I moved the ladies into their final containers a few days ago. Two are still very yellow, but seem to be growing at the same pace as the one which is very green. Slow. I really believe I stunted all my plants with high heat in the beginning. Sad, but a learning experience I suppose. I'll update this if they ever snap out of it.

 

[Waira]

..better! Hmm, topping auto's is bit of a gamble, as far as improved yields goes,.. honestly, you need to be damn good during the veg' phase, getting your girls to good size quickly,.. strain choice plays it's role as well,... done when they're too small, and all it does is set them back further... time is not on your side, so if they don't branch up and out enough by bloom, it's likely going to be a flop,... time will tell though!