So, everything was going perfect (lots of new growing and nice looking seedling), but 4/5 days ago, a little yellowing started appearing at the tips of the first set of leaves. I thought it could be nutrient burn, since my soil comes pre-loaded with nutrients - enough to last 4 weeks, as they say - and I read it could be normal in a seedling with this type of soil and that it would pass. I waited and it got worse, so I asked around for help and most people said it was N deficiency, maybe due to pH lockout. Up to that point, I hadn’t fed it any nutes, nor had I measured the pH. I went to the shop and got both. I measured the pH pre-feeding and it was around 8 (color kit, so no precise measurement), but didn’t attempt to change it as it could only be N deficiency. So, I fed it and waited. Unfortunately, it only got worse: the 2nd set of leaves is also affected. Yesterday I tried to lower the pH with vinegar (only thing I got laying around the house) and I’m currently waiting for results.
Strain: Northern Lights
Grow medium: BioBizz All-Mix Soil (NPK 4-8-6)
Light size: 60W LED
Pot size: 1/4th cut of a 2L bottle
Nutrient type and schedule: BioBizz Fish-Mix (NPK 5-3-4) - None until 3 days ago and once
Watering schedule and pH of your runoff or reservoir water: 150mL each 2 days - only started measuring pH since 3 days ago and it was ~8
What do you think it might be? I’m a bit desperate, since it was going so well, but now it looks like she’s losing…