Could be the old soil, especially if you didn't amend it. Or a watering issue. They don't look too bad though.
I was thinking the same thing they have been in there for about 2 months but I transplanted one to see the roots and it didnt look to bad. They were growing super slow I had them under a 150w ecru light I got for 30$
I have a feeling it's a combination
I had this same problem and when I switched back to my 150w any plants showing symptoms would came back out of it
look inbox i hate doing this thread shit ill fix the issue
I've had a feeling higher temps would help dry my medium faster which could be it. I'm just not sure how I want to go about that in such a small area
Would you be able to get the btus from something like a 70 watt hps. Ive used those little ones that are made to go on your garage.
You will want to buy an inside outside thermometer and insert the probe halfway down the soil line in the worst performing pot. Soil temps should never go below 68 as everything starts to move at snails pace below that temperature. Below 62 degrees and complete nutrient lockout can occur. Try adding a heated blanket at the floor level and raising your pots somehow so they do not rest directly on the cold floor. Winter months are known for causing too cool of soil temps while the ambient air temps look fine. I personally never let my air temp fall below 75 and can push as high as 92 degrees with additional CO2.
I saw a tiny space heater for 12 bucks today at walmart.